How to use the pyvips.vips_lib function in pyvips

def _get_pspec(self, name):
        # logger.debug('VipsObject.get_typeof: self = %s, name = %s',
        #              str(self), name)

        pspec = ffi.new('GParamSpec **')
        argument_class = ffi.new('VipsArgumentClass **')
        argument_instance = ffi.new('VipsArgumentInstance **')
        result = vips_lib.vips_object_get_argument(self.vobject, _to_bytes(name),
                                                   pspec, argument_class,
                                                   argument_instance)

        if result != 0:
            return None

        return pspec[0]

def new_to_file(filename):
        """Make a new stream to write to a file.

        Make a new stream that will write to the named file. For example::

            streamo = pyvips.Streamo.new_to_file("myfile.jpg")

        You can pass this stream to (for example) :meth:`write_to_stream`.

        """

        # logger.debug('VipsStreamo.new_to_file: filename = %s', filename)

        pointer = vips_lib.vips_streamo_new_to_file(_to_bytes(filename))
        if pointer == ffi.NULL:
            raise Error("can't create output stream from filename {0}"
                        .format(filename))

        return Streamo(pointer)

def cache_set_max_files(mx):
    """Limit the operation cache by number of open files."""
    vips_lib.vips_cache_set_max_files(mx)

def set_kill(self, kill):
        """Kill processing of an image.

        Use this to kill evaluation of an image. You can call it from one of
        the progress signals, for example. See :method:`set_progress`.

        """
        vips_lib.vips_image_set_kill(self.pointer, kill)

gstr_type = type_from_name('gchararray')
    genum_type = type_from_name('GEnum')
    gflags_type = type_from_name('GFlags')
    gobject_type = type_from_name('GObject')
    image_type = type_from_name('VipsImage')
    array_int_type = type_from_name('VipsArrayInt')
    array_double_type = type_from_name('VipsArrayDouble')
    array_image_type = type_from_name('VipsArrayImage')
    refstr_type = type_from_name('VipsRefString')
    blob_type = type_from_name('VipsBlob')

    pyvips.vips_lib.vips_band_format_get_type()
    format_type = type_from_name('VipsBandFormat')

    if at_least_libvips(8, 6):
        pyvips.vips_lib.vips_blend_mode_get_type()
    blend_mode_type = type_from_name('VipsBlendMode')

    # map a gtype to the name of the corresponding Python type
    _gtype_to_python = {
        gbool_type: 'bool',
        gint_type: 'int',
        guint64_type: 'long',  # Note: int and long are unified in Python 3
        gdouble_type: 'float',
        gstr_type: 'str',
        refstr_type: 'str',
        genum_type: 'str',
        gflags_type: 'int',
        gobject_type: 'GObject',
        image_type: 'Image',
        array_int_type: 'list[int]',
        array_double_type: 'list[float]',

Make a new interpolator from the libvips class nickname. For example::

            inter = pyvips.Interpolator.new('bicubic')

        You can get a list of all supported interpolators from the command-line
        with::

            $ vips -l interpolate

        See for example :meth:`.affine`.

        """

        # logger.debug('VipsInterpolate.new: name = %s', name)

        vi = vips_lib.vips_interpolate_new(_to_bytes(name))
        if vi == ffi.NULL:
            raise Error('no such interpolator {0}'.format(name))

        return Interpolate(vi)

def type_map(gtype, fn):
    """Map fn over all child types of gtype."""

    cb = ffi.callback('VipsTypeMap2Fn', fn)
    return vips_lib.vips_type_map(gtype, cb, ffi.NULL, ffi.NULL)

name (str): The name of the piece of metadata to create.
            value (mixed): The value to set as a Python value. It is
                converted to the ``gtype``, if possible.

        Returns:
            None

        Raises:
            None

        """

        gv = GValue()
        gv.set_type(gtype)
        gv.set(value)
        vips_lib.vips_image_set(self.pointer, _to_bytes(name), gv.pointer)

def __init__(self, message, detail=None):
        self.message = message
        if detail is None or detail == "":
            detail = _to_string(vips_lib.vips_error_buffer())
            vips_lib.vips_error_clear()
        self.detail = detail

        logger.debug('Error %s %s', self.message, self.detail)

def _get_pspec(self, name):
        # logger.debug('VipsObject.get_typeof: self = %s, name = %s',
        #              str(self), name)

        pspec = ffi.new('GParamSpec **')
        argument_class = ffi.new('VipsArgumentClass **')
        argument_instance = ffi.new('VipsArgumentInstance **')
        result = vips_lib.vips_object_get_argument(self.vobject,
                                                   _to_bytes(name),
                                                   pspec, argument_class,
                                                   argument_instance)

        if result != 0:
            return None

        return pspec[0]