Given this simple type:

declare Foo
clazz : Class
end

and this rule:

rule yyy
when
$f: Foo( $cl: clazz == ( java.lang.String.class ) )

1. 1. 1. $f: Foo( $cl: clazz, eval( $f.getClazz().equals( java.lang.String.class ) ) )
      2. $f: Foo( $cl: clazz == java.lang.String.class )
         then
         System.out.println( "--- got a " + $cl );
         end

Only the first vyariant is accepted by the DRL parser. Other forms are
rebuked with, e.g.:

Unable to Analyse Expression $f.getClazz().equals( java.lang.String.class ) :
[Error: Failed to compile: 2 compilation error(s):

• (1,24) unable to resolve method using strict-mode: ex10.Foo.java()
• (1,24) unqualified type in strict mode for: java]
  [Near : {... $f.getClazz().equals( java.lang.String.class ) ....}

  ]
  ^
  [Line: 1, Column: 24] : [Rule name='yyy']

Note the incorrect line number!