code: public void addMinimalEqualityToLeftOrNestedInnerJoin(CQIE query) {
          for (Function f : query.getBody()) {
              if (f.isAlgebraFunction()) {
                  addMinimalEqualityToLeftOrNestedInnerJoin(f);
              }
          }
      }
docs: *
  Adds a trivial equality to a LeftJoin in case the left join doesn't have
  at least one boolean condition. This is necessary to have syntactically
  correct LeftJoins in SQL.