Create a hash-table to hold a phone book: a set of person names and their phone numbers (e.g. Kate Wilson → +3592981981, +3598862536; Alex & Co. → 1-800-ALEX; Steve Milton → +496023456). Fill enough random data (e.g. 50,000 key-value pairs). Measure how much time it takes to perform searching by key in the hash-table using its native search capabilities, using the extension methods IEnumerable.Contains(...) and IEnumerable.Where(...). Can you explain the difference?