input: Write a python function to retrieve product prices from a database.
  assert ProductTableRetriever(database_connection).get_prices() == {'apple': 1.2, 'banana': 0.5}
  assert ProductTableRetriever(database_connection).get_prices() == {'carrot': 0.9, 'date': 3.0}
  assert ProductTableRetriever(database_connection).get_prices() == {'eggplant': 1.5, 'fig': 2.2}
output: import sqlite3
  
  class ProductTableRetriever:
      def __init__(self, connection):
          self.connection = connection
      
      def get_prices(self):
          cursor = self.connection.cursor()
          cursor.execute("SELECT product_name, price FROM products")
          prices = {row[0]: row[1] for row in cursor.fetchall()}
          cursor.close()
          return prices