code: def _has_z(self, kwargs):
          '''
          Returns True if type is 1 or 2 and z is explicitly defined in kwargs.
          '''
          return ((self._type == 1 or self._type ==2) and
                  (('z' in kwargs) or (self._element_z in kwargs))f _has_z(self, kwargs):
          '''
          Returns True if type is 1 or 2 and z is explicitly defined in kwargs.
          '''
          return ((self._type == 1 or self._type ==2) and
                  (('z' in kwargs) or (self._element_z in kwargs)))
docs: Returns True if type is 1 or 2 and z is explicitly defined in kwargs.