How to use the hpccm.common.linux_distro.UBUNTU function in hpccm

def test_detect_ubuntu_16(self):
        """Base image Linux distribution detection"""
        b = baseimage(image='ubuntu:16.04')
        self.assertEqual(hpccm.config.g_linux_distro, linux_distro.UBUNTU)
        self.assertEqual(hpccm.config.g_linux_version, StrictVersion('16.04'))

def __instructions(self):
        """String representation of the building block"""
        if hpccm.config.g_linux_distro == linux_distro.UBUNTU:
            if self.__apt:
                ospackages = self.__apt
            else:
                ospackages = self.__ospackages

            self += apt_get(aptitude=self.__aptitude,
                            download=self.__download,
                            download_directory=self.__download_directory,
                            extra_opts=self.__extra_opts,
                            extract=self.__extract,
                            keys=self.__apt_keys,
                            ospackages=ospackages,
                            ppas=self.__apt_ppas,
                            repositories=self.__apt_repositories)
        elif hpccm.config.g_linux_distro == linux_distro.CENTOS:
            if self.__yum:

def __distro(self):
        """Based on the Linux distribution, set values accordingly.  A user
        specified value overrides any defaults."""

        if hpccm.config.g_linux_distro == linux_distro.UBUNTU:
            if not self.__ospackages:
                self.__ospackages = ['file', 'hwloc', 'libevent-dev', 'make',
                                     'tar', 'wget']
                if self.__check:
                    self.__ospackages.append('perl')
            self.__runtime_ospackages = ['libevent-2.*',
                                         'libevent-pthreads-2.*']
        elif hpccm.config.g_linux_distro == linux_distro.CENTOS:
            if not self.__ospackages:
                self.__ospackages = ['file', 'hwloc', 'libevent-devel', 'make',
                                     'tar', 'wget']
                if self.__check:
                    self.__ospackages.append('perl')
            self.__runtime_ospackages = ['libevent']
        else: # pragma: no cover
            raise RuntimeError('Unknown Linux distribution')

def __distro(self):
        """Based on the Linux distribution, set values accordingly.  A user
        specified value overrides any defaults."""

        if hpccm.config.g_linux_distro == linux_distro.UBUNTU:
            if not self.__ospackages:
                self.__ospackages = ['bzip2', 'file', 'make', 'wget',
                                     'zlib1g-dev']
            self.__runtime_ospackages = ['zlib1g']
        elif hpccm.config.g_linux_distro == linux_distro.CENTOS:
            if not self.__ospackages:
                self.__ospackages = ['bzip2', 'file', 'make', 'wget',
                                     'zlib-devel']
                if self.__check:
                    self.__ospackages.append('diffutils')
            self.__runtime_ospackages = ['zlib']
        else: # pragma: no cover
            raise RuntimeError('Unknown Linux distribution')

def __distro(self):
        """Based on the Linux distribution, set values accordingly.  A user
        specified value overrides any defaults."""

        if hpccm.config.g_linux_distro == linux_distro.UBUNTU:
            if not self.__ospackages:
                self.__ospackages = ['apt-transport-https', 'ca-certificates',
                                     'gcc', 'gnupg', 'man-db',
                                     'openssh-client', 'wget']

            self.__bashrc = '/etc/bash.bashrc'

        elif hpccm.config.g_linux_distro == linux_distro.CENTOS:
            if not self.__ospackages:
                self.__ospackages = ['man-db', 'openssh-clients', 'which']

            self.__bashrc = '/etc/bashrc'

        else: # pragma: no cover
            raise RuntimeError('Unknown Linux distribution')

def __distro(self):
        """Based on the Linux distribution, set values accordingly.  A user
           specified value overrides any defaults."""

        if hpccm.config.g_linux_distro == linux_distro.UBUNTU:
            if not self.__oslabel:
                if hpccm.config.g_linux_version >= StrictVersion('18.0'):
                    self.__oslabel = 'ubuntu18.04'
                else:
                    self.__oslabel = 'ubuntu16.04'
            if not self.__ospackages:
                self.__ospackages = ['bzip2', 'openssh-client', 'tar', 'wget']

            self.__bashrc = '/etc/bash.bashrc'

        elif hpccm.config.g_linux_distro == linux_distro.CENTOS:
            if not self.__oslabel:
                if hpccm.config.g_linux_version >= StrictVersion('8.0'):
                    self.__oslabel = 'redhat8.0'
                else:
                    self.__oslabel = 'redhat7.6'

def __distro(self):
        """Based on the Linux distribution, set values accordingly.  A user
        specified value overrides any defaults."""

        if hpccm.config.g_linux_distro == linux_distro.UBUNTU:
            if not self.__ospackages:
                self.__ospackages = ['libhwloc-dev', 'make']

        elif hpccm.config.g_linux_distro == linux_distro.CENTOS:
            if not self.__ospackages:
                self.__ospackages = ['hwloc-devel', 'make']

            if hpccm.config.g_linux_version >= StrictVersion('8.0'):
                # hwloc-devel is in the CentOS powertools repository
                self.__powertools = True
        else: # pragma: no cover
            raise RuntimeError('Unknown Linux distribution')

        if self.repository:
            self.__ospackages.extend(['ca-certificates', 'git'])
        else:

def __distro(self):
        """Based on the Linux distribution, set values accordingly.  A user
           specified value overrides any defaults."""

        if hpccm.config.g_linux_distro == linux_distro.UBUNTU:
            self.__deppackages = ['libnl-3-200', 'libnl-route-3-200',
                                 'libnuma1']

            if hpccm.config.g_linux_version >= StrictVersion('18.0'):
                # Give priority to packages from the Ubuntu repositories over
                # vendor repositories
                self.__extra_opts = ['-t bionic']

                self.__ospackages= ['dapl2-utils', 'ibutils',
                                    'ibverbs-providers', 'ibverbs-utils',
                                    'infiniband-diags',
                                    'libdapl2', 'libdapl-dev',
                                    'libibmad5', 'libibmad-dev',
                                    'libibverbs1', 'libibverbs-dev',
                                    'librdmacm1', 'librdmacm-dev',
                                    'rdmacm-utils']

def __distro(self):
        """Based on the Linux distribution, set values accordingly.  A user
        specified value overrides any defaults."""

        if hpccm.config.g_linux_distro == linux_distro.UBUNTU:
            if not self.__ospackages:
                self.__ospackages = ['byacc', 'file', 'make',
                                     'openssh-client', 'wget']
            self.__runtime_ospackages = ['openssh-client']
        elif hpccm.config.g_linux_distro == linux_distro.CENTOS:
            if not self.__ospackages:
                self.__ospackages = ['byacc', 'file', 'make',
                                     'openssh-clients', 'wget']
            self.__runtime_ospackages = ['openssh-clients']
        else: # pragma: no cover
            raise RuntimeError('Unknown Linux distribution')

if self.__source:
            # Build dependencies
            if hpccm.config.g_linux_distro == linux_distro.UBUNTU:
                self.__ospackages = ['bzip2', 'file', 'gcc', 'g++', 'git',
                                     'make', 'perl', 'tar', 'wget', 'xz-utils']
            elif hpccm.config.g_linux_distro == linux_distro.CENTOS:
                self.__ospackages = ['bzip2', 'file', 'gcc', 'gcc-c++', 'git',
                                     'make', 'perl', 'tar', 'wget', 'xz']
            else: # pragma: no cover
                raise RuntimeError('Unknown Linux distribution')

        elif self.__version and not self.__source:
            # Setup the environment so that the alternate compiler version
            # is the new default
            alternatives = {}
            if hpccm.config.g_linux_distro == linux_distro.UBUNTU:
                if self.__cc:
                    alternatives['gcc'] = '$(which gcc-{})'.format(
                        self.__version)
                if self.__cxx:
                    alternatives['g++'] = '$(which g++-{})'.format(
                        self.__version)
                if self.__fortran:
                    alternatives['gfortran'] = '$(which gfortran-{})'.format(
                        self.__version)
                alternatives['gcov'] = '$(which gcov-{})'.format(
                    self.__version)
            elif hpccm.config.g_linux_distro == linux_distro.CENTOS:
                # Default for CentOS 7
                toolset_path = '/opt/rh/devtoolset-{}/root/usr/bin'.format(
                    self.__version)
                if hpccm.config.g_linux_version >= StrictVersion('8.0'):