from typing import MutableMapping
from typing import Optional
from typing import List


def extract_dependencies(content: MutableMapping) -> Optional[List[str]]:
    """
    Extract the dependencies from the Cargo.toml file.

    :param content: The Cargo.toml parsed dictionnary
    :returns: Packages listed in the dependencies section
    """
    try:
        list(content["dependencies"].keys())
    except KeyError:
        return []