what exactly is the parameter "needle" in the function test_example_element ? and from where is it being accessed?

Question

Recently i have started working on visual testing using python. I am using Needle with a python library called pytest-needle https://pypi.org/project/pytest-needle/

 from selenium.webdriver.common.by import By
 import pytest

 @pytest.mark.element
 def test_example_element(needle):
 """Example for comparing individual elements

:param NeedleDriver needle: NeedleDriver instance
:return:
"""

# Navigate to web page
needle.driver.get('https://www.google.com')

# Take an element screen diff
needle.assert_screenshot('search_field', (By.ID, 'tsf'))

can anyone explain what exactly is needle in the line below? and from where is it being accessed?
def test_example_element(needle):