(self, docnum, fieldname)
Returns True if the given document has a term vector for the given
        field.
Returns True if the given document has a term vector for the given
        field.
Returns True if the given document has a term vector for the given field .
def has_vector(self, docnum, fieldname):
        """Returns True if the given document has a term vector for the given
        field.
        """
        raise NotImplementedError
def has_vector ( self , docnum , fieldname ) : raise NotImplementedError