question: public static boolean isNullConversion ( MethodType call , MethodType recv , boolean keepInterfaces ) { if ( call == recv ) return true ; int len = call . parameterCount ( ) ; if ( len != recv . parameterCount ( ) ) return false ; for ( int i = 0 ; i < len ; i ++ ) if ( ! isNullConversion ( call . parameterType ( i ) , recv . parameterType ( i ) , keepInterfaces ) ) return false ; return isNullConversion ( recv . returnType ( ) , call . returnType ( ) , keepInterfaces ) ; }
target:  True if a method handle can receive a call under a slightly different method type, without moving or reformatting any stack elements.