Write a Julia program that generates a heatmap of a given data set. The heatmap should have appropriate labels on both axes, a color bar legend, and a title. The heatmap should be visually clear and appropriately scaled to the data. The program should be flexible enough to allow for customization of the colorscheme and other styling options. Additionally, the program should be able to handle missing or incomplete data and display it appropriately in the heatmap.
This prompt doesn't seem malicious.