def get_value(key, &block)
      key   = key.to_sym
      value = @table[key]

      if block_given?
        block.arity == 0 ? value.instance_eval(&block) : block.call(value)
      end

      value
    end
def get_value(key, &block)
      key   = key.to_sym
      value = @table[key]

      if block_given?
        block.arity == 0 ? value.instance_eval(&block) : block.call(value)
      end

      value
    end
Returns a value for +key+ from settings table.
 Yields +value+ of +key+ if +block+ provided.

 == Examples:

   .key do |key|
     ...
   end

   # or

   .key do
     ...
   end