###
This example checks that all non-physiological protonation
states of ASP, GLU, LYS, HIS are detected correctly. It also
checks that the HIS tautomers are correctly identified.

## modifications
GLU7  -> protonated
LYS33 -> deprotonated
ASP18 -> protonated
HIS15 -> d-tautomer
## unmodifed residues as control
LYS96
LYS97
LYS116
GLU35
ASP48
ASP48
ASP52 (... and more)
