"""Create fallback_executor
Generated by Phi-Octopus Eden
2025-11-08 17:13:24.041096
"""

```python
from typing import Callable, Any

class FallbackExecutor:
    """
    A class for creating a fallback mechanism in function execution.
    
    This allows defining primary functions that may fail due to errors,
    and secondary backup functions that are invoked if the primary fails.
    """

    def __init__(self, primary_function: Callable[..., Any], 
                 fallback_function: Callable[..., Any]):
        """
        Initialize FallbackExecutor with a primary function and a fallback.

        :param primary_function: The main function to execute.
        :param fallback_function: The backup function to use if the primary fails.
        """
        self.primary_function = primary_function
        self.fallback_function = fallback_function

    def __call__(self, *args: Any, **kwargs: Any) -> Any:
        """
        Execute the primary function. If it raises an exception,
        execute the fallback function.

        :param args: Arguments to pass to the functions.
        :param kwargs: Keyword arguments to pass to the functions.
        :return: The result of the successfully executed function or None.
        """
        try:
            return self.primary_function(*args, **kwargs)
        except Exception as e:
            print(f"Error occurred in primary function: {e}")
            fallback_result = self.fallback_function(*args, **kwargs)
            print("Fallback function executed.")
            return fallback_result

def sample_primary_function(x: int) -> int:
    """
    Example of a primary function that may fail.
    
    :param x: An input integer to process.
    :return: The result of the processing or None in case of an error.
    """
    try:
        # Simulate division by zero for demonstration
        return 10 / (x - 5)
    except ZeroDivisionError as e:
        raise Exception("Primary function encountered a critical error.") from e

def sample_fallback_function(x: int) -> int:
    """
    Example of a fallback function.
    
    :param x: An input integer to process.
    :return: A default value in case the primary function fails.
    """
    return 100 - x

# Example usage
if __name__ == "__main__":
    # Create an instance of FallbackExecutor with sample functions
    executor = FallbackExecutor(sample_primary_function, sample_fallback_function)
    
    # Run the executor with a value that should cause failure
    result = executor(5)  # This will trigger fallback
    print(f"Result: {result}")
```