question: public static boolean isUniformCollection ( Collection < ? > c , Class < ? > e ) { if ( e == null ) { throw new IllegalArgumentException ( "Null reference type" ) ; } if ( c == null ) { throw new IllegalArgumentException ( "Null collection" ) ; } if ( c . isEmpty ( ) ) { return false ; } for ( Object o : c ) { if ( o == null || ! e . isAssignableFrom ( o . getClass ( ) ) ) { return false ; } } return true ; }
target:  Check if the given collection is a uniform collection of the given type.