question: public DateTimeFormatterBuilder appendLiteral ( String text ) { if ( text == null ) { throw new IllegalArgumentException ( "Literal must not be null" ) ; } switch ( text . length ( ) ) { case 0 : return this ; case 1 : return append0 ( new CharacterLiteral ( text . charAt ( 0 ) ) ) ; default : return append0 ( new StringLiteral ( text ) ) ; } }
target:  Instructs the printer to emit specific text, and the parser to expect it. The parser is case-insensitive.