Cannot convert null literal to non-nullable reference type.

Non-nullable field '_elementProvider' must contain a non-null value when exiting constructor. Consider declaring the field as nullable.

Non-nullable field '_residueProvider' must contain a non-null value when exiting constructor. Consider declaring the field as nullable.

Non-nullable field '_lookup' must contain a non-null value when exiting constructor. Consider declaring the field as nullable.

Non-nullable field '_chemicalProteoformHashGenerator' must contain a non-null value when exiting constructor. Consider declaring the field as nullable.

Dereference of a possibly null reference.

Converting null literal or possible null value to non-nullable type.

Dereference of a possibly null reference.

Non-nullable field '_elementProvider' must contain a non-null value when exiting constructor. Consider declaring the field as nullable.