def METHOD_NAME():
    """
    Read a PDB file describing a protein with a cystein bridge and cystein
    residues that are not involved in a bridge. Embed the content of the PDB in
    a :class:`vermouth.system.System`.
    Note that the PDB file does contain water, ions, and ligands in addition to
    the protein. The ligand bonds are explicitely provided as CONECT records.
    The edges from the CONECT records are removed from the system, so there is
    no edge left.
    """
    molecules = read_pdb(PDB_CYS)
    assert len(molecules) == 1
    molecule = molecules[0]
    molecule.remove_edges_from(list(molecule.edges))
    system = vermouth.system.System()
    system.molecules = [molecule]
    assert len(system.molecules[0].edges) == 0
    return system