def check_key_value_hash(item)
      return (item.kind_of?(Hash) && item.include?(:key) &&
          item.include?(:value) && (item.keys.size == 2))
    end
def check_key_value_hash(item)
      return (item.kind_of?(Hash) && item.include?(:key) &&
          item.include?(:value) && (item.keys.size == 2))
    end
Checks if the argument is hash and has exactly ':key' and ':value' keys.