The CollapseWhiteSpace method is a static extension method provided by the SandboxSystemExtensions class. It is used to process a string by collapsing consecutive whitespace characters into a single space. This can be useful for normalizing text input where multiple spaces, tabs, or newlines should be reduced to a single space for consistency.

To use the CollapseWhiteSpace method, simply call it on any string instance. This method is an extension method, so it can be called as if it were a method on the string class itself.

Example usage:

string input = "This   is   a   test   string.";
string result = input.CollapseWhiteSpace();
// result: "This is a test string."