question: @ 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 { return null ; } }
target:  Returns the network parameters for the given string paymentProtocolID or NULL if not recognized. 