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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _SignedBinaryURNFromID(binary_id ):
 """Converts a SignedBinaryID to the equivalent AFF4 URN."""

  binary_type = binary_id.binary_type
  if binary_type == rdf_objects.SignedBinaryID.BinaryType.PYTHON_HACK:
    return GetAFF4PythonHackRoot().Add(binary_id.path)
  elif binary_type == rdf_objects.SignedBinaryID.BinaryType.EXECUTABLE:
    return GetAFF4ExecutablesRoot().Add(binary_id.path)
  else:
    raise ValueError("Unknown binary type %s." % binary_type)