This code is a macro written in Jinja2, a powerful template engine for Python. This macro, named var_dump, works similarly to PHP's var_dump() function. It helps to print or display structured information about variables, especially useful for debugging.
The var_dump macro takes four parameters:
- 
var: The variable you want to display.
- 
var_name: The name of the variable (this is optional, and its default value is an empty string).
- 
space: The indentation level (this is optional, and its default value is 0).