code: def find_fields(self, classname=".*", fieldname=".*", fieldtype=".*", accessflags=".*"):
          
          for cname, c in self.classes.items():
              if re.match(classname, cname):
                  for f in c.get_fields():
                      z = f.get_field()
                      if re.match(fieldname, z.get_name()) and \
                         re.match(fieldtype, z.get_descriptor()) and \
                         re.match(accessflags, z.get_access_flags_string()):
                          yield f
docs: find fields by regex
  
          :param classname: regular expression of the classname
          :param fieldname: regular expression of the fieldname
          :param fieldtype: regular expression of the fieldtype
          :param accessflags: regular expression of the access flags
          :rtype: generator of `FieldClassAnalysis`