If argument sbmlf is an object of class character,the
function returns TRUE, if no infos, warnings, errors or fatals
have been found. Otherwise a the value returned is a list.
infos Infos
warnings Warnings
errors Errors
fatals Fatals
Each entry of one of these lists is again a list containing the message id,
line and column number of the SBML file generating the message and the
corresponding message text. If argument sbmlf is an object of class '>sbmlPtr,
the function returns the number of errors found in the SBML document.