'Constructs a new feature extractor.
Args:
depth_multiplier: float depth multiplier for feature extractor
Returns:
an ssd_meta_arch.SSDFeatureExtractor object.'

def _create_feature_extractor(self, depth_multiplier):

    min_depth = 32
    conv_hyperparams = {}
    return ssd_mobilenet_v1_feature_extractor.SSDMobileNetV1FeatureExtractor(depth_multiplier, min_depth, conv_hyperparams)
