"""Create fallback_executor
Generated by Phi-Octopus Eden
2025-11-07 00:17:09.817038
"""

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


class FallbackExecutor:
    """
    A class for executing a main task function while providing fallback behavior in case of errors.
    
    This implementation allows for graceful error handling by attempting to execute a fallback function if the main
    task encounters an exception. The fallback method can be specified or default behavior is to simply print an error message.
    
    Example usage:
        def main_function(x: int) -> int:
            return x * 2
        
        def fallback_function(x: int) -> int:
            return (x - 10) + 5

        executor = FallbackExecutor(main_function, fallback_function)
        
        result = executor.execute(10)  # Returns 20
        print(result)  # Output: 20
        
        try:
            result = executor.execute('a')  # Raises TypeError
        except TypeError as e:
            print(f"Error occurred: {e}")
        fallback_result = executor.fallback_execute('a')  # Returns -5
        print(fallback_result)  # Output: -5

    Args:
        main_function (Callable[[Any], Any]): The function to be executed.
        fallback_function (Optional[Callable[[Any], Any]]): An optional function to handle errors, defaults to None.
    """

    def __init__(self, main_function: Callable[[Any], Any], fallback_function: Optional[Callable[[Any], Any]] = None) -> None:
        self.main_function = main_function
        self.fallback_function = fallback_function

    def execute(self, *args: Any, **kwargs: Any) -> Any:
        """
        Execute the main function with given arguments.
        
        Args:
            *args: Positional arguments to pass to `main_function`.
            **kwargs: Keyword arguments to pass to `main_function`.
            
        Returns:
            The result of executing `main_function(*args, **kwargs)`.
            
        Raises:
            Any exception raised by `main_function`.
        """
        try:
            return self.main_function(*args, **kwargs)
        except Exception as e:
            print(f"Main function error: {e}")
            if self.fallback_function is not None:
                return self.fallback_function(*args, **kwargs)

    def fallback_execute(self, *args: Any, **kwargs: Any) -> Any:
        """
        Execute the fallback function with given arguments if it exists.
        
        Args:
            *args: Positional arguments to pass to `fallback_function`.
            **kwargs: Keyword arguments to pass to `fallback_function`.
            
        Returns:
            The result of executing `fallback_function(*args, **kwargs)`, or None if no fallback is defined.
        """
        return self.fallback_function(*args, **kwargs) if self.fallback_function else None


# Example usage
def main_function(x: int) -> int:
    return x * 2

def fallback_function(x: int) -> int:
    return (x - 10) + 5

executor = FallbackExecutor(main_function, fallback_function)

try:
    result = executor.execute(10)
except Exception as e:
    print(f"Error occurred: {e}")
else:
    print(result)  # Output: 20

try:
    result = executor.execute('a')
except TypeError as e:
    print(f"Error occurred: {e}")
fallback_result = executor.fallback_execute('a')
print(fallback_result)  # Output: -5
```