| Add(Double, T) | Add a value to the set on the current chainage location. This will fail if set is global. |
| Add(Double, T, Boolean) | Add a value to the set on the current chainage location. This will fail if set is global. |
| Add(Double, Double, T) | Add a value defined within the given span. This corresponds to adding the value at the start and end location of the span. |