code: public TransactionInput addSignedInput(TransactionOutput output, ECKey signingKey, SigHash sigHash, boolean anyoneCanPay) {
          return addSignedInput(output.getOutPointFor(), output.getScriptPubKey(), signingKey, sigHash, anyoneCanPay);
      }
docs: Adds an input that points to the given output and contains a valid signature for it, calculated using the
  signing key.