code: Symbol lookupMethod(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, MethodCheck methodCheck, LookupHelper lookupHelper) {
          MethodResolutionContext resolveContext = new MethodResolutionContext();
          resolveContext.methodCheck = methodCheck;
          return lookupMethod(env, pos, location, resolveContext, lookupHelper);
      }
docs: Main overload resolution routine. On each overload resolution step, a
  lookup helper class is used to perform the method/constructor lookup;
  at the end of the lookup, the helper is used to validate the results
  (this last step might trigger overload resolution diagnostics).