Write a python function to do the following
Given an array of ints, return the number of 9's in the array.
array_count9([1, 2, 9]) → 1
array_count9([1, 9, 9]) → 2
array_count9([1, 9, 9, 3, 9]) → 3
# Your code here
Write some tests for your functions. What are some edge cases you might consider?
# Your code here
Build up on this example, and write a function that takes a second optional argument that allows up to count any number passed in. It should default to 9.
# Your code here
Write some tests for your functions. What are some edge cases you might consider?
# Your code here