code: def detect_feature(a, b=None):
      """
      Detect the feature used in a relay program.
  
      Parameters
      ----------
      a : Union[tvm.relay.Expr, tvm.IRModule]
        The input expression or module.
  
      b : Optional[Union[tvm.relay.Expr, tvm.IRModule]]
        The input expression or module.
        The two arguments cannot both be expression or module.
  
      Returns
      -------
      features : Set[Feature]
        Features used in the program.
      """
      if isinstance(a, IRModule):
          a, b = b, a
      return {Feature(int(x)) for x in _ffi_api.detect_feature(a, b)}
  
imports: from ...ir import IRModule
  from ...relay import transform, build_module
  from ...runtime.ndarray import cpu
  from .None import _ffi_api
  from .feature import Feature
label_desc: Use image node_id 15 for calling a global function with example usage: detect_feature(a, b) and returns: unknown