public boolean equals(Object object) { if (!(object instanceof Expression)) { return false; } Expression e = (Expression) object; if (e.getType() != getType() || e.getOperandCount() != getOperandCount()) { return false; } // compare operands int len = e.getOperandCount(); for (int i = 0; i < len; i++) { if (!Util.nullSafeEquals(e.getOperand(i), getOperand(i))) { return false; } } return true; }