A 
_Warning 
instance represents one warning emitted through the Python warning system 
(
warnings).  This is used to insulate callers of 
_collectWarnings
from changes to the Python warnings system which might otherwise require 
changes to the warning objects that function passes to the observer object 
it accepts.
| Instance Variables | message | The string which was passed as the message parameter to 
warnings.warn.
 | 
 | category | The Warning subclass which was passed as the category 
parameter to warnings.warn.
 | 
 | filename | The name of the file containing the definition of the code object which 
was stacklevel frames above the call to 
warnings.warn, where stacklevel is the value of 
the stacklevel parameter passed to 
warnings.warn.
 | 
 | lineno | The source line associated with the active instruction of the code 
object object which was stacklevel frames above the call to 
warnings.warn, where stacklevel is the value of 
the stacklevel parameter passed to 
warnings.warn.
 |