Fix typo in function doc-string
@@ -166,7 +166,7 @@ class SimpleFeatureExtraction(beam.PTransform):
"""The feature extraction (element-wise transformations).
We create a `PTransform` class. This `PTransform` is a bundle of
- transformations that cann be applied to any other pipeline as a step.
+ transformations that can be applied to any other pipeline as a step.
We'll extract all the raw features here. Due to the nature of `PTransform`s,
we can only do element-wise transformations here. Anything that requires a
