When calling chain.address_type_txes() with a block range that has 0 transactions of the specified address type, the script hangs and eventually throws a "std::bad_alloc" error.

Example:
txes_protocol = chain.address_type_txes(511645, 511646, blocksci.address_type.nulldata)`

Error:
MemoryError: std::bad_alloc

I've also reproduced this behavior with address type of multisig, eg. block 170.