'Perform transformations on a given image.
Args:
output_encoding: A value from OUTPUT_ENCODING_TYPES.
quality: A value between 1 and 100 to specify the quality of the
encoding.  This value is only used for JPEG & WEBP quality control.
parse_source_metadata: when True the metadata (EXIF) of the source image
is parsed before any transformations. The results can be retrieved
via Image.get_original_metadata.
transparent_substition_rgb: When transparent pixels are not support in the
destination image format then transparent pixels will be substituted
for the specified color, which must be 32 bit rgb format.
rpc: A UserRPC object.
Returns:
str, image data after the transformations have been performed on it.
Raises:
BadRequestError when there is something wrong with the request
specifications.
NotImageError when the image data given is not an image.
BadImageError when the image data given is corrupt.
LargeImageError when the image data given is too large to process.
InvalidBlobKeyError when the blob key provided is invalid.
TransformtionError when something errors during image manipulation.
AccessDeniedError: when the blobkey refers to a Google Storage object, and
the application does not have permission to access the object.
ObjectNotFoundError:: when the blobkey refers to an object that no longer
exists.
Error when something unknown, but bad, happens.'

def execute_transforms(self, output_encoding=PNG, quality=None, parse_source_metadata=False, transparent_substitution_rgb=None, rpc=None):

    rpc = self.execute_transforms_async(output_encoding=output_encoding, quality=quality, parse_source_metadata=parse_source_metadata, transparent_substitution_rgb=transparent_substitution_rgb, rpc=rpc)
    return rpc.get_result()
