docs: @Nullable
      public static NetworkParameters fromPmtProtocolID(String pmtProtocolId) {
          if (pmtProtocolId.equals(PAYMENT_PROTOCOL_ID_MAINNET)) {
              return MainNetParams.get();
          } else if (pmtProtocolId.equals(PAYMENT_PROTOCOL_ID_TESTNET)) {
              return TestNet3Params.get();
          } else if (pmtProtocolId.equals(PAYMENT_PROTOCOL_ID_UNIT_TESTS)) {
              return UnitTestParams.get();
          } else if (pmtProtocolId.equals(PAYMENT_PROTOCOL_ID_REGTEST)) {
              return RegTestParams.get();
          } else {
              return null;
          }
      }