LibSBML is a native library for reading, writing and manipulating files and data streams containing the Systems Biology Markup Language (SBML). It offers language bindings for C, C++, C#, Java, JavaScript, MATLAB, Perl, PHP, Python, R and Ruby.
The original version of these files was indeed wrong as per the failure they are supposed to test, but it's slightly more likely that someone might make a mistake putting in a correctly-spelled-but-incorrectly-placed 'modifierSpeciesReference' than they are to put in an incorrectly-spelled-and-also-incorrectly-placed 'modiferSpeciesReference'.
The original version of these files was indeed wrong as per the failure they are supposed to test, but it's slightly more likely that someone might make a mistake putting in a correctly-spelled-but-incorrectly-placed 'modifierSpeciesReference' than they are to put in an incorrectly-spelled-and-also-incorrectly-placed 'modiferSpeciesReference'.
See #372.