How to use the pixiedust.utils.environment.Environment.pixiedustHome function in pixiedust

def cmd(self, command, module):
        # create node_modules
        home = Environment.pixiedustHome
        node_home = os.path.join(home,'node')
        node_modules = os.path.join(node_home,'node_modules')
        if not os.path.exists(node_modules):
            os.makedirs(node_modules)

        # create sub-process
        npm_path = self.which('npm')
        args = [npm_path, command, '-s']
        if (module):
            if (isinstance(module, str)):
                args.append(module)
            else:
                args.extend(module)
        print (' '.join(args))
        ps = subprocess.Popen( args, stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, cwd = node_home)

def __init__(self):
        """
        Establishes the Node's home directories and executable paths
        """
        # get the home directory
        home = Environment.pixiedustHome

        # Node home directory
        self.node_home = os.path.join(home, 'node')
        if not os.path.exists(self.node_home):
            os.makedirs(self.node_home)

        # Node modules home directory
        self.node_modules = os.path.join(self.node_home, 'node_modules')
        if not os.path.exists(self.node_modules):
            os.makedirs(self.node_modules)

        self.node_prog = 'node'
        self.npm_prog = 'npm'
        if platform.system() == 'Windows':
            self.node_prog += '.exe'
            self.npm_prog += '.cmd'