"""Create fact_checker
Generated by Phi-Octopus Eden
2025-11-06 07:27:10.989875
"""

```python
from typing import List, Dict, Any


class FactChecker:
    """
    A simple fact checking system that verifies if a statement is true or false based on given facts.
    
    Args:
        knowledge_base: A dictionary containing key-value pairs where the keys are statements and values are their truthfulness (True/False).
        
    Methods:
        check_fact: Takes a statement and checks if it's in the knowledge base, returning its truth value if found; otherwise returns None.
    """
    def __init__(self, knowledge_base: Dict[str, bool]):
        self.knowledge_base = knowledge_base

    def check_fact(self, statement: str) -> bool:
        """
        Checks if a given statement is true or false based on the stored knowledge base.

        Args:
            statement (str): The statement to be checked for truthfulness.

        Returns:
            bool: True if the statement is found and marked as true in the knowledge base; False if it's found and marked as false; None otherwise.
        """
        return self.knowledge_base.get(statement, None)


# Example usage
if __name__ == "__main__":
    # Create a fact checker with a simple knowledge base
    kb = {"Earth is round": True, "4+5=9": False, "Python is fun to learn": True}
    fact_checker = FactChecker(kb)

    # Check some facts
    print(fact_checker.check_fact("Earth is round"))  # Output: True
    print(fact_checker.check_fact("4+5=9"))          # Output: False
    print(fact_checker.check_fact("Python is hard to learn"))  # Output: None (Not found)
```