"""Create fallback_executor
Generated by Phi-Octopus Eden
2025-11-07 11:09:23.682089
"""

```python
class FallbackExecutor:
    """
    A class that provides a fallback mechanism for executing functions in case of errors.
    
    This implementation allows you to define primary and secondary functions to execute,
    providing robust error recovery capabilities.

    :param primary_func: The main function to be executed. It should accept positional arguments.
    :type primary_func: callable
    :param secondary_func: An optional fallback function that will attempt execution in case the primary function fails.
    :type secondary_func: callable, default=None
    """

    def __init__(self, primary_func: callable, secondary_func: callable = None):
        self.primary_func = primary_func
        self.secondary_func = secondary_func

    def execute(self, *args) -> any:
        """
        Execute the primary function with provided arguments. If it fails,
        attempt to execute the secondary function if provided.

        :param args: Positional arguments for the primary function.
        :return: The result of the executed function or None in case both functions fail.
        """
        try:
            return self.primary_func(*args)
        except Exception as e:
            print(f"Error occurred while executing {self.primary_func.__name__}: {e}")
            
            if self.secondary_func:
                try:
                    return self.secondary_func(*args)
                except Exception as e:
                    print(f"Secondary function also failed: {e}")
                    return None
            else:
                print("No fallback function available.")
                return None

# Example Usage
def primary_add(a, b):
    """Add two numbers."""
    return a + b

def secondary_subtract(a, b):
    """Subtract the second number from the first one as an alternative operation."""
    return a - b

# Create an instance of FallbackExecutor with both functions provided.
fallback_executor = FallbackExecutor(primary_add, secondary_subtract)

# Example calls
print(fallback_executor.execute(10, 5))  # Expected: 15 (Primary function success)
print(fallback_executor.execute(10, 'five'))  # Expected: Error message and None (Primary function failure with fallback)
```