Sentence Searcher

Create a function that returns the whole of the first sentence which contains a specific word. Include the full stop at the end of the sentence.

Examples

txt = "I have a cat. I have a mat. Things are going swell."

sentence_searcher(txt, "have") ➞ "I have a cat."

sentence_searcher(txt, "MAT") ➞ "I have a mat."

sentence_searcher(txt, "things") ➞ "Things are going swell."

sentence_searcher(txt, "flat") ➞ ""

Notes

• Sentences will always end with a period.
• Your function should not be case sensitive.
• Return an empty string if the word isn't found in the sentence.