remove incorrect sentence from docs
add doc paragraph on faster CFLAGS for test environments
use known type to avoid some overhead
use known type to avoid some overhead
use known type to avoid some overhead
use known type to avoid some overhead
use known type to avoid some overhead
use known type to avoid some overhead
clean up indentation in string
add test for refcycle with Element proxies
add missing import
minor code simplification
declare internal TreeBuilder methods as final (requires moving them before their calls due to Cython bug)
remove unnecessary c-isms
comment