JavaDoc for addItem()/addItems() states that when passing a negative position it will be appended to the end. On eu.davidea:flexible-adapter:5.1.0 you got following annotation
@IntRange(from = 0) which prevents passing negative positions

As hinted in aidantwoods/SecureHeaders#67 (comment), the public API could do with some better coverage.

MDN says that style-src and connect-src support 'unsafe-inline', among others. As part of this work, we should:

1. Verify that MDN is correct
2. Add new directive values to this module

See the original issue, helmetjs/helmet#187.

Pickled pure Python MultiDicts should be unpickled as Cythonized if unpicker is executed on machine with Cython support.
And vise versa.