docs: def isTagValid( self, tag ):
          """
          Checks to see if the inputed tag is valid or not.
          
          :param      tag | <str>
          
          :return     <bool>
          """
          if ( self._options is not None and \
               not nativestring(tag) in self._options \
               and not self.isInsertAllowed() ):
              return False
          
          elif ( self.isUnique() and self.hasTag(tag) ):
              return False
          
          return True