"""Create fact_checker
Generated by Phi-Octopus Eden
2025-11-06 12:21:46.723433
"""

```python
from typing import List, Dict


class FactChecker:
    """
    A simple fact-checking class that verifies facts against a predefined database.
    """

    def __init__(self):
        self.knowledge_base: Dict[str, bool] = {
            "The Earth is round": True,
            "Humans have been to the moon": True,
            "Pandas are bears": True,
            "Water boils at 100 degrees Celsius under standard atmospheric pressure": True,
            "Python is an easy language to learn": True
        }

    def check_fact(self, fact: str) -> bool:
        """
        Check if a given fact is true based on the knowledge base.

        :param fact: The fact to be checked.
        :return: True if the fact is true according to the database, False otherwise.
        """
        return self.knowledge_base.get(fact, False)

    def add_fact(self, fact: str, truth_value: bool) -> None:
        """
        Add a new fact to the knowledge base.

        :param fact: The fact to be added.
        :param truth_value: True if the fact is true, False otherwise.
        """
        self.knowledge_base[fact] = truth_value


# Example usage
def main():
    checker = FactChecker()
    
    # Check existing facts
    print(checker.check_fact("The Earth is round"))  # Expected output: True
    
    # Add a new fact and check again
    checker.add_fact("AI can understand human emotions", False)
    print(checker.check_fact("AI can understand human emotions"))  # Expected output: False


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

This code defines a `FactChecker` class with methods to check facts against a predefined knowledge base and add new facts. The example usage demonstrates how to use the class to verify existing facts and add a new one.