merge!

# File lib/bundler/vendor/thor/lib/thor/core_ext/ordered_hash.rb, line 95
        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