def get_row_generator(self, ref, cache=None):
from inspect import isgenerator<EOL>from rowgenerators import get_generator<EOL>g = get_generator(ref)<EOL>if not g:<EOL><INDENT>raise GenerateError("<STR_LIT>".format(type(ref), ref))<EOL><DEDENT>else:<EOL><INDENT>return g<EOL><DEDENT>
Return a row generator for a reference