The `StFile` class has a number of typos where the documentation does not match the columns. For example, the correct attribute is `I_x`, and not `Ix`. There is also a problem with the torsional stiffness, which is called `K` in the HAWC2 manual, and the `StFile` documentation, but is accessed via `I_p`. For this we have two options: - Fix the documentation. - Cause a breaking change by changing its name to `K`. Also, `set_value()` although straightforward to use is not documented.