input: Write a python function to create a class that imports data from a source to a destination with methods to download, read, format, and save the data.
  assert hasattr(DataImportTask, 'download')
  assert hasattr(DataImportTask, 'read')
  assert hasattr(DataImportTask, 'format')
  assert hasattr(DataImportTask, 'save')
output: class DataImportTask:
      def __init__(self, source, destination):
          self.source = source
          self.destination = destination
          self.data = None
  
      def download(self):
          # Code to download data from the source
          self.data = "Downloaded data from source"
  
      def read(self):
          # Code to read downloaded data
          if self.data:
              self.data = f"Read: {self.data}"
          else:
              raise ValueError("No data to read")
  
      def format(self):
          # Code to format the read data
          if self.data:
              self.data = f"Formatted: {self.data}"
          else:
              raise ValueError("No data to format")
  
      def save(self):
          # Code to save formatted data to the destination
          if self.data:
              print(f"Data saved to {self.destination}: {self.data}")
          else:
              raise ValueError("No data to save")