"""Create fallback_executor
Generated by Phi-Octopus Eden
2025-11-08 02:06:43.822256
"""

```python
from typing import Any, Callable, Dict, Optional


class FallbackExecutor:
    """
    A class for creating a fallback mechanism in function execution.
    
    When an error occurs during the execution of a primary function,
    this class can attempt to execute a backup function as a recovery measure.

    Attributes:
        primary_func (Callable): The main function to be executed.
        backup_func (Optional[Callable]): The optional backup function to be
            called in case the primary function fails. Defaults to None.
    """

    def __init__(self, primary_func: Callable, backup_func: Optional[Callable] = None):
        """
        Initializes FallbackExecutor with a primary and optional backup function.

        Args:
            primary_func (Callable): The main function to attempt execution.
            backup_func (Optional[Callable], optional): A fallback function. Defaults to None.
        """
        self.primary_func = primary_func
        self.backup_func = backup_func

    def execute(self, *args: Any, **kwargs: Any) -> Any:
        """
        Attempts to execute the primary function with given arguments.

        If an exception occurs during execution, attempts to run the backup function,
        if provided. Returns the result of the executed function or None on failure.

        Args:
            args (Any): Positional arguments passed to the primary function.
            kwargs (Any): Keyword arguments passed to the primary function.

        Returns:
            Any: The return value of the successfully executed function, or None.
        """
        try:
            return self.primary_func(*args, **kwargs)
        except Exception as e:
            if self.backup_func is not None:
                print(f"Primary function failed with error: {e}")
                return self.backup_func(*args, **kwargs)
            else:
                print(f"No backup function available. Primary function failed with error: {e}")
                return None


# Example usage
def primary_function(x: int, y: int) -> int:
    """A simple addition function."""
    return x + y

def backup_function(x: int, y: int) -> int:
    """A backup function that returns a fixed value."""
    print("Using backup function.")
    return 0


if __name__ == "__main__":
    # Create an instance of FallbackExecutor with the primary and backup functions
    fallback = FallbackExecutor(primary_function, backup_func=backup_function)
    
    # Successful execution
    result = fallback.execute(10, y=20)
    print(f"Result: {result}")  # Expected output: Result: 30
    
    # Failed execution (raises an error) but handled by the backup function
    try:
        raise ValueError("An intentional failure for demonstration purposes")
    except ValueError as e:
        result = fallback.execute(10, y=20)
        print(f"Result after exception handling: {result}")  # Expected output: Result after exception handling: Using backup function. 0
```