"""Create fallback_executor
Generated by Phi-Octopus Eden
2025-11-07 07:59:34.068088
"""

```python
from typing import Callable, Optional


class FallbackExecutor:
    """
    A class for creating a fallback mechanism in execution.
    
    This implementation allows for setting up a primary function that may fail,
    and provides an optional secondary function as a backup to handle the failure.
    If the primary function fails, the secondary function is executed instead.
    """

    def __init__(self, primary: Callable[[], None], fallback: Optional[Callable[[], None]] = None):
        """
        Initialize the FallbackExecutor with primary and optional fallback functions.

        :param primary: The primary function to be executed. It should take no arguments and return nothing.
        :param fallback: An optional secondary function that serves as a fallback. It also takes no arguments and returns nothing.
        """
        self.primary = primary
        self.fallback = fallback

    def execute(self) -> None:
        """
        Execute the primary function, or fall back to the secondary function if an error occurs.

        :return: None
        """
        try:
            self.primary()
        except Exception as e:
            print(f"Primary execution failed with exception: {e}")
            if self.fallback is not None:
                self.fallback()


def example_usage():
    """
    Example usage of FallbackExecutor.
    
    This function demonstrates how to use the FallbackExecutor class by defining
    a primary and fallback functions, then using them within an instance of the class.
    """
    def primary_function() -> None:
        print("Executing primary function.")
        raise ValueError("Primary function encountered an error.")

    def fallback_function() -> None:
        print("Executing fallback function as primary execution failed.")

    # Create an instance with a primary and a fallback function
    executor = FallbackExecutor(primary=primary_function, fallback=fallback_function)

    # Execute the setup. The fallback should be triggered due to the raised error.
    executor.execute()

if __name__ == "__main__":
    example_usage()
```