def translation(translation):
    """ Construct a homogeneous 2D translation matrix.
    # Arguments
        translation: the translation 2D vector
    # Returns
        the translation matrix as 3 by 3 numpy array
    """
    return np.array([
        [1, 0, translation[0]],
        [0, 1, translation[1]],
        [0, 0, 1]
    ])
 Construct a homogeneous 2D translation matrix.
    # Arguments
        translation: the translation 2D vector
    # Returns
        the translation matrix as 3 by 3 numpy array
    
keras_retinanet/utils/transform.py