48         private bool hasValue;  field in Google.Protobuf.ExtensionValue
60             if (!hasValue)  in CalculateSize()
71                 hasValue = hasValue,  in Clone()
83                 && hasValue.Equals((other as ExtensionValue<T>).hasValue)  in Equals()
93                 hash = hash * 31 + hasValue.GetHashCode();  in GetHashCode()
102             hasValue = true;  in MergeFrom()
111                 if (extensionValue.hasValue)  in MergeFrom()
113                     hasValue |= codec.FieldMerger(ref field, extensionValue.field);  in MergeFrom()
120             if (hasValue)  in WriteTo()
135             hasValue = true;  in SetValue()
139         public bool HasValue => hasValue;