OEReceptorAddExtraMol
OEReceptorAddExtraMol(rec: Union[OEGraphMol,OEMol,OEQMol],
arg2: Union[OEGraphMol,OEMol,OEQMol]) -> bool
Adds a copy of extraMol to receptor’s extra molecules.
Returns true if successful.
It is only valid to call this function if receptor is a valid receptor
(i.e., OEIsReceptor returns true).