def default_select(identifier, all_entry_points):
 if (len(all_entry_points) == 0):
  raise PluginMissingError(identifier)
 elif (len(all_entry_points) == 1):
  return all_entry_points[0]
 elif (len(all_entry_points) > 1):
  raise AmbiguousPluginError(all_entry_points)

def default_select ( identifier , all_entry_points ) : if ( len ( all_entry_points ) == 0 ) : raise PluginMissingError ( identifier ) elif ( len ( all_entry_points ) == 1 ) : return all_entry_points [ 0 ] elif ( len ( all_entry_points ) > 1 ) : raise AmbiguousPluginError ( all_entry_points )
raise an exception when we have ambiguous entry points .