 
   @doc """
   Collapse any new lines and whitespace following this
-  node and emitting up to `max` new lines.
+  node, emitting up to `max` new lines.
   """
   @spec collapse_lines(pos_integer) :: doc_collapse
   def collapse_lines(max) when is_integer(max) and max > 0 do

  end

  @doc """
  Introduces a flex break.

  A flex break still causes a group to break, like
  a regular break, but it is re-evaluated when the
  documented is processed.

  This function is used by `container_doc/4` and friends
  to the maximum number of entries on the same line.
  """
  @spec flex_break(binary) :: doc_break
  def flex_break(string \\ " ") when is_binary(string) do

  end

  @doc ~S"""
  Returns a break document based on the given `string`.

  This break can be rendered as a linebreak or as the given `string`,
  depending on the `mode` of the chosen layout.
