deep_merge

# File activesupport/lib/active_support/core_ext/hash/deep_merge.rb, line 7
        def deep_merge(other_hash)
          self.merge(other_hash) do |key, oldval, newval|
            oldval = oldval.to_hash if oldval.respond_to?(:to_hash)
            newval = newval.to_hash if newval.respond_to?(:to_hash)
            oldval.class.to_s == 'Hash' && newval.class.to_s == 'Hash' ? oldval.deep_merge(newval) : newval
          end
        end