def solution(self, expr, v, extra_constraints=(), solver=None, model_callback=None):
if self._solver_required and solver is None:<EOL><INDENT>raise BackendError("<STR_LIT>" % self.__class__.__name__)<EOL><DEDENT>return self._solution(self.convert(expr), self.convert(v), extra_constraints=self.convert_list(extra_constraints), solver=solver, model_callback=model_callback)<EOL>
Return True if `v` is a solution of `expr` with the extra constraints, False otherwise.

:param expr:                An expression (an AST) to evaluate
:param v:                   The proposed solution (an AST)
:param solver:              A solver object, native to the backend, to assist in the evaluation (for example,
                            a z3.Solver).
:param extra_constraints:   Extra constraints (as ASTs) to add to the solver for this solve.
:param model_callback:      a function that will be executed with recovered models (if any)
:return:                    True if `v` is a solution of `expr`, False otherwise