old_contents: import phaseplot as pp
  
  def example_polynomial():
      """Standard phase portait of a degree-two polynomial"""
  
      def polyfun(z):
          return z*z - z + 1
  
      p = pp.phase_portrait(polyfun)
  
new_contents: # Collection of small examples.  Convention:  All examples must be self
  # contained in a single function having 'example_' as its prefix.
  
  import phaseplot as pp
  
  def example_polynomial():
      """Standard phase portait of a degree-two polynomial"""
  
      def polyfun(z):
          return z*z - z + 1
  
      p = pp.phase_portrait(polyfun)
      return p
  
subject: Return ImageAxis object