"""Create fallback_executor
Generated by Phi-Octopus Eden
2025-11-08 16:11:35.188565
"""

```python
class FallbackExecutor:
    """
    A class designed to handle execution tasks with fallback mechanisms in case of errors.

    Attributes:
        primary_executor (callable): The primary function or method that should be executed.
        backup_executors (list[callable]): A list of functions or methods that will be tried as backups if the
                                           primary executor fails.
        error_handler (callable, optional): A function to handle specific exceptions. If provided, it's used instead
                                            of raising an exception.

    Methods:
        execute: Attempts to run the primary_executor and falls back to backup_executors if necessary.
    """

    def __init__(self, primary_executor: callable, backup_executors: list[callable], error_handler=None):
        """
        Initialize the FallbackExecutor with primary and backup executors.

        :param primary_executor: The main function or method to execute.
        :param backup_executors: A list of fallback functions or methods.
        :param error_handler: Optional function to handle specific exceptions, defaults to None.
        """
        self.primary_executor = primary_executor
        self.backup_executors = backup_executors
        self.error_handler = error_handler

    def execute(self, *args, **kwargs) -> any:
        """
        Execute the primary executor and fallback if necessary.

        :param args: Positional arguments to pass to the executors.
        :param kwargs: Keyword arguments to pass to the executors.
        :return: The result of the successful execution or an error message.
        """
        try:
            return self.primary_executor(*args, **kwargs)
        except Exception as e:
            if not callable(self.error_handler):
                for executor in self.backup_executors:
                    try:
                        return executor(*args, **kwargs)
                    except Exception:
                        continue
                raise  # No backups were successful and no error handler is provided.
            else:
                return self.error_handler(e)

# Example usage

def primary_function(x):
    return x * 2

def backup1_function(x):
    return x + 3

def backup2_function(x):
    return x - 5

def custom_error_handler(error):
    print(f"An error occurred: {error}")
    return "Default value"

fallback_executor = FallbackExecutor(primary_function, [backup1_function, backup2_function], custom_error_handler)

result = fallback_executor.execute(4)
print(result)  # Expected output: 8 (from primary_function)
```