@staticmethod
def _filter_tests(function, tests):
    """Filter tests with condition 'function(test_node) == True'"""
    result = {}
    for module_name in tests:
        for test_name in tests[module_name]['tests']:
            if function(module_name, test_name, tests):
                if module_name not in result:
                    result[module_name] = {'ast': tests[module_name]['ast'],
                        'source_path': tests[module_name]['source_path'],
                        'import_valid': tests[module_name]['import_valid'],
                        'tests': {}}
                result[module_name]['tests'][test_name] = tests[module_name][
                    'tests'][test_name]
    return result
