   @doc """
   Works like `binary_to_atom` but the atom must exist.
 
+  ## Examples
+
       :my_atom                          #=> :my_atom
       binary_to_existing_atom "my_atom" #=> :my_atom
 

  Returns the atom whose text representation is
  `some_binary` in UTF8 encoding.

      binary_to_atom "my_atom" #=> :my_atom

  """

  @doc """
  Returns a binary which corresponds to the text representation
  of `some_atom` in UTF8 encoding.

  ## Examples

      atom_to_binary :my_atom #=> "my_atom"

