title: Multiline return value statements in Python doctests
body: <p>I am testing a function that produces results that are very long when represented, and I don't know how to fit that result into the doctest.</p>
  
  <p>In this example, I'm using pscyopg2, which has verbose representations for its composed queries (<a href="https://stackoverflow.com/questions/4879804/use-psycopg2-to-construct-queries-without-connection">details as to why</a>)</p>
  
  <pre><code>from psycopg2.sql import Literal, Composed
  
  def foo(a, b):
    """
    Examples:
      &gt;&gt;&gt; foo('one', 'two')
      Composed([SQL('SELECT * FROM my_table WHERE a='), Literal('one'), SQL(' AND b='), Literal('two')])
    """
  </code></pre>
  
  <p>The result line can get really long, and I'm wondering if it's possible to break it up into multiple lines, like the input expression with <code>...</code></p>