// the `invoke` member function. In this case, we use the `calleeExpression` in the `KtCallExpression` as the PSI
            // representation of this receiver. Caller can then use this PSI for further call resolution, which is implemented by the
            // parameter `resolveCalleeExpressionOfFunctionCall` in `toKtCallInfo`.
            var explicitReceiverPsi = when (psi) {