Jasmine test errors

Hi team,
I’ve been running into an issue using Jasmine SpyOn to write unit tests with the latest Contentful version.

For example:
spyOn(Contentful, 'createClient').and.returnValue(mockObject());
Returns an error like:
Error: <spyOn> : createClient is not declared writable or has no setter.

It looks this error only happens using version 10.0.0 and higher, so I’ve had to downgrade in the meantime. Would anyone happen to know why this might be happening? Thank you