| obj | Object to search for the method. | 
| functionName | Function name to search for. | 
| argumentTypes | Argument types for the function. | 
Given an object, function name, and a list of argument types; find the method that matches.
| objectType | Object type to search for the method. | 
| functionName | Function name to search for. | 
| argumentTypes | Argument types for the function. | 
Given an object type, function name, and a list of argument types; find the method that matches.