@staticmethod
def _encode_block_string(block):
    """Encodes a block to a string."""
    args = ['r%d' % block.num_repeat, 'k%d' % block.kernel_size, 's%d%d' %
        (block.strides[0], block.strides[1]), 'e%s' % block.expand_ratio, 
        'i%d' % block.input_filters, 'o%d' % block.output_filters]
    if 0 < block.se_ratio <= 1:
        args.append('se%s' % block.se_ratio)
    if block.id_skip is False:
        args.append('noskip')
    return '_'.join(args)
