question: public Builder addEngineSettings ( final String engineName , final List < String > imports , final List < String > staticImports , final List < String > scripts , final Map < String , Object > config ) { if ( null == imports ) throw new IllegalArgumentException ( "imports cannot be null" ) ; if ( null == staticImports ) throw new IllegalArgumentException ( "staticImports cannot be null" ) ; if ( null == scripts ) throw new IllegalArgumentException ( "scripts cannot be null" ) ; final Map < String , Object > m = null == config ? Collections . emptyMap ( ) : config ; settings . put ( engineName , new EngineSettings ( imports , staticImports , scripts , m ) ) ; return this ; }
target:  Add a particular script engine for the executor to instantiate.