presto-main/src/main/java/io/prestosql/sql/relational/VariableReferenceExpression.java/VariableReferenceExpression/equals
class VariableReferenceExpression:    @Override
    public boolean equals(Object obj)
    {
        if (this == obj) {
            return true;
        }
        if (obj == null || getClass() != obj.getClass()) {
            return false;
        }
        VariableReferenceExpression other = (VariableReferenceExpression) obj;
        return Objects.equals(this.name, other.name) && Objects.equals(this.type, other.type);
    }