static boolean joinEqualityExpression(
      Expression expression, Collection<Symbol> leftSymbols, Collection<Symbol> rightSymbols) {
    return joinComparisonExpression(
        expression,
        leftSymbols,
        rightSymbols,
        ImmutableSet.of(ComparisonExpression.Operator.EQUAL));
  }
If the expression is EQUAL ComparisonExpression

@return true if the expression is EQUAL ComparisonExpression and leftSymbols contains
    expression.getLeft() and rightSymbols contains expression.getRight().
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/relational/planner/optimizations/JoinUtils.java