Time dependent error when executing pytest.

# Issue
## Problem Description
In the branch #95, when I run pytest sometimes I get the error as in the README. It is not a systematic behavior, most of the times the test passes correctly. It seems to be a time-dependent error.
## Expected Behavior
This should not happen.
## What Needs to be Done
Test and check if someone can reproduce the issue and possibly fix it.
## How Can It Be Tested or Reproduced
Running pytest.