用法
Args args = new Args(Schema.of("l:boolean:false p:int:8080 u:string:root f:boolean:false"),ArgLine.of("-l -p 8080 -u root "));
assertThat(args.argValue("l"), is(true));
assertThat(args.argValue("p"), is(8080));
assertThat(args.argValue("u"), is("root"));
assertThat(args.argValue("f"), is(false));