text: import datetime
  import time
  
  
  class BadFunctionCallOutput(Exception):
      """
      We failed to decode ABI output.
  
      Most likely ABI mismatch.
      """
      pass
  
  
  class BlockNumberOutofRange(Exception):
      '''
      block_identifier passed does not match known block.
      '''
      pass
  
  
  class CannotHandleRequest(Exception):
      """
      Raised by a provider to signal that it cannot handle an RPC request and
      that the manager should proceed to the next provider.
      """
      pass
  
  
  class InvalidAddress(ValueError):
      """
      The supplied address does not have a valid checksum, as defined in EIP-55
      """
      pass
  
  
  class NameNotFound(ValueError):
      """
      Raised when a caller provides an Ethereum Name Service name that
      does not resolve to an address.
      """
      pass
  
  
  class StaleBlockchain(Exception):
      """
      Raised by the stalecheck_middleware when the latest block is too old.
      """
      def __init__(self, block, allowable_delay):
          last_block_date = datetime.datetime.fromtimestamp(block.timestamp).strftime('%c')
          message = (
              "The latest block, #%d, is %d seconds old, but is only allowed to be %d s old. "
              "The date of the most recent block is %s. Continue syncing and try again..." %
              (block.number, time.time() - block.timestamp, allowable_delay, last_block_date)
          )
          super().__init__(message, block, allowable_delay)
  
      def __str__(self):
          return self.args[0]
  
  
  class UnhandledRequest(Exception):
      """
      Raised by the manager when none of it's providers responds to a request.
      """
      pass
  
  
  class MismatchedABI(Exception):
      """
      Raised when an ABI does not match with supplied parameters, or when an
      attempt is made to access a function/event that does not exist in the ABI.
      """
      pass
  
  
  class FallbackNotFound(Exception):
      """
      Raised when fallback function doesn't exist in contract.
      """
      pass
  
  
  class ValidationError(Exception):
      """
      Raised when a supplied value is invalid.
      """
      pass
  
  
  class NoABIFunctionsFound(AttributeError):
      """
      Raised when an ABI doesn't contain any functions.
      """
      pass
  
  
  class NoABIEventsFound(AttributeError):
      """
      Raised when an ABI doesn't contain any events.
      """
      pass
  
  
  class InsufficientData(Exception):
      """
      Raised when there are insufficient data points to
      complete a calculation
      """
      pass
  
  
  class TimeExhausted(Exception):
      """
      Raised when a method has not retrieved the desired result within a specified timeout.
      """
      pass
  