code: def __add__(self, other):
      if isinstance(other, DummySpec):
          # nothing
          return self
  
      """
              array + other_feature -> [my_elements, other]
              array + other_array -> [my_elements, other_elements]
              layer + ? -> fail
          """
      if isinstance(other, FeatureSpec):
          if isinstance(other, FeatureSpecArray):
              return FeatureSpecArray(
                  *self.__elements, *other.__elements
              )
  
          elif other.kind != "plot":
              return FeatureSpecArray(*self.__elements, other)
  
      return super().__add__(other)
  
imports: import io
  import json
  import os
  from typing import Union
  from lets_plot._global_settings import get_global_bool, has_global_value, FRAGMENTS_ENABLED
label_desc: Use image node_id 4 for calling the FeatureSpecArray obj's underlying member method code with example usage: obj.__add__(other) and returns: super, self, FeatureSpecArray, FeatureSpecArray