code: def validateOneAttribute(self, ctxt, elem, attr, value):
          
          if ctxt is None: ctxt__o = None
          else: ctxt__o = ctxt._o
          if elem is None: elem__o = None
          else: elem__o = elem._o
          if attr is None: attr__o = None
          else: attr__o = attr._o
          ret = libxml2mod.xmlValidateOneAttribute(ctxt__o, self._o, elem__o, attr__o, value)
          return ret
docs: Try to validate a single attribute for an element basically
            it does the following checks as described by the XML-1.0
            recommendation: - [ VC: Attribute Value Type ] - [ VC:
            Fixed Attribute Default ] - [ VC: Entity Name ] - [ VC:
            Name Token ] - [ VC: ID ] - [ VC: IDREF ] - [ VC: Entity
            Name ] - [ VC: Notation Attributes ]  The ID/IDREF
             uniqueness and matching are done separately