Issue #, if available:
Custom statements are being generated once each for every path in the api causing regression in the sam generated api swagger.
Description of changes:
Check for copies when appending to list.
Description of how you validated changes:
unit test
Checklist:

• Write/update tests
• make pr passes
• Update documentation
• Verify transformed template deploys and application functions as expected
• Add/update example to examples/2016-10-31

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.