question: public I buildInvocation ( Object protocolKey , I invocation ) throws ConfigException { Objects . requireNonNull ( invocation ) ; invocation = buildInvocation ( invocation ) ; LruCache < Object , I > invocationCache = _invocationCache ; if ( invocationCache != null ) { I oldInvocation ; oldInvocation = invocationCache . get ( protocolKey ) ; if ( oldInvocation != null && ! oldInvocation . isModified ( ) ) { return oldInvocation ; } if ( invocation . getURLLength ( ) < _maxURLLength ) { invocationCache . put ( protocolKey , invocation ) ; } } return invocation ; }
target:  Builds the invocation, saving its value keyed by the protocol key.