code: public static int[] validate6NonNegative(int[] data, String paramName){
          validateNonNegative(data, paramName);
          return validate6(data, paramName);
      }
docs: Reformats the input array to a length 6 array and checks that all values >= 0.
  
  If the array is length 1, returns [a, a, a, a, a, a]
  If the array is length 3, return [a, a, b, b, c, c]
  If the array is length 6, returns the array.
  
  @param data An array
  @param paramName The param name, for error reporting
  @return An int array of length 6 that represents the input