Error: during expansion of (jimport ...) - unbound variable: class

        Call history:

        <syntax>          (quote (jimport java.lang.String jstring))
        <syntax>          (##core#quote (jimport java.lang.String jstring))
        <eval>    (print (expand* (quote (jimport java.lang.String jstring))))
        <eval>    (expand* (quote (jimport java.lang.String jstring)))
        expand-full.scm:31: expand        
        <eval>    (r (quote begin))
        <eval>    (r (quote define))
        <eval>    (r (quote class))
        <eval>    (cadr x)
        <eval>    (string-append (symbol->string (caddr x)) "-")
        <eval>    (symbol->string (caddr x))
        <eval>    (caddr x)
        <eval>    (string->symbol (string-append prefix "class"))
        <eval>    (string-append prefix "class")
        <eval>    (methods (class class-symbol))
        <eval>    (class class-symbol)  <--