@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + ((expr == null) ? 0 : expr.hashCode());
return result;
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + ((unit == null) ? 0 : unit.hashCode());
result = prime * result + ((value == null) ? 0 : value.hashCode());
return result;
}