question: private Object queryCommandValue ( final String commandIdentifier ) { Check . notNull ( commandIdentifier , "command" ) ; final StringBuffer cmd = new StringBuffer ( ) ; cmd . append ( "return editor.queryCommandValue(\"" ) ; cmd . append ( commandIdentifier ) ; cmd . append ( "\") || ''" ) ; return browser . evaluate ( cmd . toString ( ) ) ; }
target:  Gets the value of the document, range, or selection for the given command.