# File lib/sass/util/ordered_hash.rb, line 152
  def merge!(other_hash)
    if block_given?
      other_hash.each {|k, v| self[k] = key?(k) ? yield(k, self[k], v) : v}
    else
      other_hash.each {|k, v| self[k] = v}
    end
    self
  end