def _is_carboxy_terminus(pdb_object):
  """
  Checks if an atom or residue is part of a carboxy terminus.

  Parameters
  ----------
  pdb_object : iotbx.pdb.hierarchy.atom or iotbx.pdb.hierarchy.residue_group or
               iotbx.pdb.hierarchy.atom_group

  Returns
  -------
  bool

  .. note:: Deprecated in favor ChemicalEnvironment._get_chemical_environment in
            the SVM code.
  """
  atoms = None
  if (type(pdb_object).__name__ == "atom"):
    atoms = pdb_object.parent().atoms()
  else :
    assert (type(pdb_object).__name__ in ['residue_group','atom_group'])
    atoms = pdb_object.atoms()
  for atom in atoms :
    if (atom.name.strip() == "OXT"):
      return True
  return False