   end
 
   @doc """
-  Returns true if the current module defines a callback.
+  Returns `true` if the current module defines a callback.
   This function is only available for modules being compiled.
   """
   def defines_callback?(module, name, arity) do

  end

  @doc """
  Returns all types available from the beam.

  It is returned as a list of tuples where the first
  element is the type (`:typep`, `:type` and `:opaque`).

  The module has to have a corresponding beam file
  on the file system.
  """
  def beam_types(module) do
    case abstract_code(module) do


  @doc """
  Defines a spec.
  This macro is the one responsible for handling the attribute `@spec`.

  ## Examples

