old_contents: """Provide a (g)dbm-compatible interface to bsdhash.hashopen."""
  
  import bsddb
  
  error = bsddb.error
  
  def open(file, flag, mode=0666):
      return bsddb.hashopen(file, flag, mode)
  
new_contents: """Provide a (g)dbm-compatible interface to bsdhash.hashopen."""
  
  import bsddb
  
  error = bsddb.error                     # Exported for anydbm
  
  def open(file, flag, mode=0666):
      return bsddb.hashopen(file, flag, mode)
  
subject: Clarify why we define error. Suggested by Andrew Dalke.