How to use the pydeps.py2depgraph.py2dep function in pydeps

def depgrf(item, args=""):
    return py2dep(item, **empty(args))

# Pass args as a **kw dict since we need to pass it down to functions
    # called, but extract locally relevant parameters first to make the
    # code prettier (and more fault tolerant).
    colors.START_COLOR = kw.get('start_color')
    show_cycles = kw.get('show_cycles')
    nodot = kw.get('nodot')
    no_output = kw.get('no_output')
    output = kw.get('output')
    fmt = kw['format']
    show_svg = kw.get('show')
    reverse = kw.get('reverse')
    if os.getcwd() != trgt.workdir:
        # the tests are calling _pydeps directoy
        os.chdir(trgt.workdir)

    dep_graph = py2depgraph.py2dep(trgt, **kw)

    if kw.get('show_deps'):
        cli.verbose("DEPS:")
        pprint.pprint(dep_graph)

    dotsrc = depgraph_to_dotsrc(trgt, dep_graph, **kw)

    if not nodot:
        if kw.get('show_dot'):
            cli.verbose("DOTSRC:")
            print(dotsrc)

        if not no_output:
            svg = dot.call_graphviz_dot(dotsrc, fmt)
            if fmt == 'svg':
                svg = svg.replace(b'', b'<style>.edge>path:hover{stroke-width:8}</style>')

def externals(trgt, **kwargs):
    """Return a list of direct external dependencies of ``pkgname``.
       Called for the ``pydeps --externals`` command.
    """
    kw = dict(
        T='svg', config=None, debug=False, display=None, exclude=[], exclude_exact=[],
        externals=True, format='svg', max_bacon=2**65, no_config=True, nodot=False,
        noise_level=2**65, noshow=True, output=None, pylib=True, pylib_all=True,
        show=False, show_cycles=False, show_deps=False, show_dot=False,
        show_raw_deps=False, verbose=0, include_missing=True, start_color=0
    )
    kw.update(kwargs)
    depgraph = py2depgraph.py2dep(trgt, **kw)
    pkgname = trgt.fname
    log.info("DEPGRAPH: %s", depgraph)
    pkgname = os.path.splitext(pkgname)[0]

    res = {}
    ext = set()

    for k, src in list(depgraph.sources.items()):
        if k.startswith('_'):
            continue
        if not k.startswith(pkgname):
            continue
        if src.imports:
            imps = [imp for imp in src.imports if not imp.startswith(pkgname)]
            if imps:
                for imp in imps: