code: public Binder spread(int count) {
          if (count == 0) {
              return dropLast();
          }
  
          Class<?> aryType = type().parameterType(type().parameterCount() - 1);
  
          assert aryType.isArray();
  
          Class<?>[] spreadTypes = new Class[count];
          Arrays.fill(spreadTypes, aryType.getComponentType());
  
          return spread(spreadTypes);
      }
docs: Spread a trailing array argument into the given number of arguments of
  the type of the array.
  
  @param count the new count of arguments to spread from the trailing array
  @return a new Binder