<filename>mmdet/models/utils/builder.py
from mmcv.utils import Registry,build_from_cfg

TRANSFORMER = Registry('Transformer')
POSITIONAL_ENCODING = Registry('Position encoding')

def build_transformer(cfg,default_args=None):
    """Builder for Transfomer."""
    return build_from_cfg(cfg,TRANSFORMER,default_args)

def build_positional_encoding(cfg,default_args=None):
    """Builder for Position Encoding."""
    return build_from_cfg(cfg,POSITIONAL_ENCODING,default_args)