The column of the marker uses zero-based indexing, even though the doc comment at its definition claims to use one-based indexing, and the line actually uses one-based indexing. Because the fields are private, the documentation of the getter functions are the only visible documentation in the docs, and they don't say whether they use one- or zero-based indexing, which meant that I had to dig into the code to find this inconsistency and had to wrap it with a helper function to correct for it.