   end
 
   @doc """
-  Flattens the given `list` of nested lists. An optional
-  tail can be given that will be added at the end of
-  the flattened list.
+  Flattens the given `list` of nested lists.
 
   ## Examples
 
       iex> List.flatten([1, [[2], 3]])
       [1,2,3]
 
+  """
+  def flatten(list) do
+    :lists.flatten(list)
+  end
+
+  @doc """
+  Flattens the given `list` of nested lists. 
+  The list `tail` will be added at the end of
+  the flattened list.
+
+  ## Examples
+
       iex> List.flatten([1, [[2], 3]], [4, 5])
       [1,2,3,4,5]
 
   """
-  def flatten(list) do
-    :lists.flatten(list)
-  end
-
   def flatten(list, tail) do
     :lists.flatten(list, tail)
   end


  @doc """
  Receives a list of tuples and deletes the first tuple
  where the item at position `position` matches with the
  given `item`. Returns the new tuple.

  ## Examples



  @doc """
  Receives a list of tuples and sorts the items
  at `position` of the tuples. The sort is stable.

  ## Examples

