def find_type_conversion(source_type, target_type):
    """
    Find the operator name for converting source_type into target_type
    """
    if type(source_type) == type(target_type):
        return 'identity'
    elif type(target_type) == FloatTensorType:
        return 'imageToFloatTensor'
    else:
        raise ValueError('Unsupported type conversion from %s to %s' % (
                         source_type, target_type))
Find the operator name for converting source_type into target_type