def validate_user_email(self, value):
enterprise_customer = self.context.get('<STR_LIT>')<EOL>try:<EOL><INDENT>user = User.objects.get(email=value)<EOL>return models.EnterpriseCustomerUser.objects.get(<EOL>user_id=user.id,<EOL>enterprise_customer=enterprise_customer<EOL>)<EOL><DEDENT>except (models.EnterpriseCustomerUser.DoesNotExist, User.DoesNotExist):<EOL><INDENT>pass<EOL><DEDENT>return value<EOL>
Validates the user_email, if given, to see if an existing EnterpriseCustomerUser exists for it.

If it does not, it does not fail validation, unlike for the other field validation methods above.