<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def chk_associations(self, fout_err="gaf.err"):
 """Check that fields are legal in GAF"""

        obj = GafData("2.1")
        return obj.chk(self.associations, fout_err)