def deep_merge(other_hash)
      r = {}
      merge(other_hash)  do |key, oldval, newval|
        r[key] = oldval.class == self.class ? oldval.deep_merge(newval) : newval
      end
    end
def deep_merge(other_hash)
      r = {}
      merge(other_hash)  do |key, oldval, newval|
        r[key] = oldval.class == self.class ? oldval.deep_merge(newval) : newval
      end
    end
Recursive version of Hash#merge

 Compared with Hash#merge!, this method supports nested hashes.
 When both +hsh+ and +other_hash+ contains an entry with the same key,
 it merges and returns the values from both arrays.

 Compared with Hash#merge, this method provides a different approch
 for merging nasted hashes.
 If the value of a given key is an Hash and both +other_hash+ abd +hsh
 includes the same key, the value is merged instead replaced with
 +other_hash+ value.

    h1 = {"a" => 100, "b" => 200, "c" => {"c1" => 12, "c2" => 14}}
    h2 = {"b" => 254, "c" => 300, "c" => {"c1" => 16, "c3" => 94}}
    h1.rmerge(h2)    #=> {"a" => 100, "b" => 254,
                          "c" => {"c1" => 16, "c2" => 14, "c3" => 94}}

 Simply using Hash#merge would return

    h1.merge(h2)     #=> {"a" => 100, "b" = >254,
                          "c" => {"c1" => 16, "c3" => 94}}