Write and test a Python function common$\_$pair, that checks whether any two consecutive characters of left match any two consecutive characters in right. The function should return the first two matching characters it finds or the empty string if there is no match.

Complete the function in the following cell. We have provided some tests; your tutor may use additional tests.

$\%$run $-$i m$269\_$util

$$

$$

def common$\_$pair$($left: str$,$ right: str$)->$ str:

pass # Delete this and replace with your answer here

$$

$$

common$\_$pair$\_$tests $=[$

# case, left, right, common pair

$(\text{'}$one is empty', 'ACTG', $\text{'}\text{'},\text{'}\text{'}),$

$(\text{'}$same string', 'ACTG', 'ACTG', $\text{'}$AC$\text{'}),$

$(\text{'}$nothing common', 'ACCA', $\text{'}$GTGT$\text{'},\text{'}\text{'}),$

$(\text{'}$subsequence$\text{'},$ 'AAAA', 'GATTA', $\text{'}\text{'})$

$]$

$$

test$($common$\_$pair, common$\_$pair$\_$tests$)$