Implement a Function 'get_when' in an In-Memory Database

Implement a get_when feature in an in-memory database. Assume an in-memory database supports sequential insertion and querying. Implement a function get_when that returns the timestamp of the earliest record satisfying a condition. Requirements: You will receive an array of events in chronological order, each event includes a timestamp and several fields. Implement: A method to insert events. A method to query the earliest timestamp of an event satisfying a condition, i.e., get_when(predicate). The condition is defined by a passed function predicate(event) returning a boolean. Input format: event objects include fields: timestamp (an integer, representing the timestamp), data (any data type, representing other event information). predicate is a function taking an event object as input and returning a boolean. Output format: The get_when method should return an integer representing the earliest timestamp of an event meeting the condition; return -1 if no such event exists. Constraints: Timestamps are unique and inserted in ascending order. Up to 10^5 events. Example: # Suppose there is the following sequence of events E = [ {'timestamp': 1, 'data': 'A'}, {'timestamp': 2, 'data': 'B'}, {'timestamp': 3, 'data': 'C'} ] # Query condition def is_event_B(event): return event['data'] == 'B' # get_when returns 2 because 'B' first appears at timestamp 2 Example Input {'timestamp': 1, 'data': 'A'} {'timestamp': 2, 'data': 'B'} {'timestamp': 3, 'data': 'C'} is_event_B B