def _Kane_constant_symbols(self):
        from_eoms, from_sym_lists = self._Kane_inlist_insyms()
        if sympy_equal_to_or_newer_than('0.7.6'):
            unique_symbols = set()
            for expr in from_eoms:
                unique_symbols = unique_symbols.union(expr.free_symbols)
            constants = unique_symbols
        else:
            constants = set(self.eom_method._find_othersymbols(
                *self._Kane_inlist_insyms()))
        constants.remove(dynamicsymbols._t)
        return constants
Similar to ``_find_othersymbols()``, except it checks all syms used in
dataset/ETHPy150Open pydy/pydy/pydy/system.py/System._Kane_constant_symbols