def nop(self, expression, progress=False, delay=False):
expression = _ensure_string_from_expression(expression)<EOL>def map(ar):<EOL><INDENT>pass<EOL><DEDENT>def reduce(a, b):<EOL><INDENT>pass<EOL><DEDENT>return self.map_reduce(map, reduce, [expression], delay=delay, progress=progress, name='<STR_LIT>', to_numpy=False)<EOL>
Evaluates expression, and drop the result, usefull for benchmarking, since vaex is usually lazy