parameters: (self)
docstring: A :class:`.ColumnCollection` that represents the "exported"
          columns of this :class:`.Selectable`.
  
          The "exported" columns represent the collection of
          :class:`.ColumnElement` expressions that are rendered by this SQL
          construct.   There are two primary varieties which are the
          "FROM clause columns" of a FROM clause, such as a table, join,
          or subquery, and the "SELECTed columns", which are the columns in
          the "columns clause" of a SELECT statement.
  
          .. versionadded:: 1.4
  
          .. seealso:
  
              :attr:`.FromClause.exported_columns`
  
              :attr:`.SelectBase.exported_columns`
docstring_summary: A :class:`.ColumnCollection` that represents the "exported"
          columns of this :class:`.Selectable`.
docstring_tokens: A : class : . ColumnCollection that represents the exported columns of this : class : . Selectable .
function: def exported_columns(self):
          """A :class:`.ColumnCollection` that represents the "exported"
          columns of this :class:`.Selectable`.
  
          The "exported" columns represent the collection of
          :class:`.ColumnElement` expressions that are rendered by this SQL
          construct.   There are two primary varieties which are the
          "FROM clause columns" of a FROM clause, such as a table, join,
          or subquery, and the "SELECTed columns", which are the columns in
          the "columns clause" of a SELECT statement.
  
          .. versionadded:: 1.4
  
          .. seealso:
  
              :attr:`.FromClause.exported_columns`
  
              :attr:`.SelectBase.exported_columns`
          """
  
          raise NotImplementedError()
function_tokens: def exported_columns ( self ) : raise NotImplementedError ( )