'Checks if the input data shape is valid'

def check_data_shape(self, data_shape):

    if (not (len(data_shape) == 3)):
        raise ValueError('data_shape    should    have    length    3,    with    dimensions    CxHxW')
    if (not (data_shape[0] == 3)):
        raise ValueError('This    iterator    expects    inputs    to    have    3    channels.')
