# How to verify the “random sampling” Gauss-Markov Assumption with Stata (or anything else)?

According to the book I am using, Introductory Econometrics by J.M. Wooldridge, there are 5 Gauss-Markov assumptions necessary to obtain BLUE.

However, by looking in other literature, there is one of Wooldridge's assumption I do not recognize, i.e. the so-called "Random Sampling" assumption according to which "We have a random sample of n observations $$(x_{i1}, x_{i2}, \dots, x_{ik}, y_i): i= 1, \dots, n)$$ following the population model".

I am trying to figure out how to test this assumption on my data, knowing that my supervisor is looking for a proof more solid than simply saying my data was obtained randomly.