Fix error with no state found

Author: ktalluri456

sdks/python/apache_beam/runners/worker/operations.pxd

@@ -83,6 +83,7 @@ cdef class Operation(object):
   cdef readonly object scoped_start_state
   cdef readonly object scoped_process_state
   cdef readonly object scoped_finish_state
+  cdef readonly object scoped_timer_processing_state
 
   cdef readonly object data_sampler
 

sdks/python/apache_beam/runners/worker/operations.py

@@ -444,12 +444,16 @@ def __init__(
     self.metrics_container = MetricsContainer(self.name_context.metrics_name())
 
     self.state_sampler = state_sampler
-    self.scoped_start_state = self.state_sampler.scoped_state(
-        self.name_context, 'start', metrics_container=self.metrics_container)
-    self.scoped_process_state = self.state_sampler.scoped_state(
-        self.name_context, 'process', metrics_container=self.metrics_container)
-    self.scoped_finish_state = self.state_sampler.scoped_state(
-        self.name_context, 'finish', metrics_container=self.metrics_container)
+    self.scoped_start_state = None
+    self.scoped_process_state = None
+    self.scoped_finish_state = None
+    if self.state_sampler:
+      self.scoped_start_state = self.state_sampler.scoped_state(
+          self.name_context, 'start', metrics_container=self.metrics_container)
+      self.scoped_process_state = self.state_sampler.scoped_state(
+          self.name_context, 'process', metrics_container=self.metrics_container)
+      self.scoped_finish_state = self.state_sampler.scoped_state(
+          self.name_context, 'finish', metrics_container=self.metrics_container)
     # TODO(ccy): the '-abort' state can be added when the abort is supported in
     # Operations.
     self.receivers = []  # type: List[ConsumerSet]