def merge_default(defaults)
      if defaults && !defaults.empty?
        defaults.each do |key, value|
          self[key] = value unless self.key?(key)
        end
      end
      self
    end
def merge_default(defaults)
      if defaults && !defaults.empty?
        defaults.each do |key, value|
          self[key] = value unless self.key?(key)
        end
      end
      self
    end
Update hash with default parameters for non existing keys