   end
 
   @doc """
-  Returns the head of a list; raises `ArgumentError` if the list is empty.
+  Returns the head of a list. Raises `ArgumentError` if the list is empty.
 
   Allowed in guard tests. Inlined by the compiler.
 


      iex> round(5.6)
      6
      iex> round(5.2)
      5
      iex> round(-9.9)
      -10

  """
  @spec round(float) :: integer

  end

  @doc """
  A non-local return from a function.

  Check `Kernel.SpecialForms.try/1` for more information.

  Inlined by the compiler.
  """
