Fuzz introspector: fuzz_char_lib
For issues and ideas: https://github.com/ossf/fuzz-introspector/issues

Fuzzer calltree

0 LLVMFuzzerTestOneInput [function] [call site] 00000
1 count_lowercase_letters [function] [call site] 00001
2 printf [call site] 00002
2 printf [call site] 00003