docs: def _database_exists(self):
          """
          Check if the database exists.
  
          """
          con = psycopg2.connect(host=self.host, database="postgres",
              user=self.user, password=self.password, port=self.port)
          query_check = "select datname from pg_catalog.pg_database"
          query_check += " where datname = '{0}';".format(self.dbname)
          c = con.cursor()
          c.execute(query_check)
          result = c.fetchall()
          if len(result) > 0:
              return True
          return False