"""Format file size in a human-readable format.

This function converts a given size in bytes into a more readable format by scaling it
to the appropriate unit (B, KB, MB, GB, TB). The function handles edge cases such as
zero bytes and ensures the output is formatted to one decimal place.

Args:
    bytes_size (int): The size in bytes to be formatted.

Returns:
    str: A string representing the size in a human-readable format, rounded to one
         decimal place and suffixed with the appropriate unit (B, KB, MB, GB, TB).

Examples:
    >>> format_size(500)
    '500.0 B'
    >>> format_size(1024)
    '1.0 KB'
    >>> format_size(5242880)
    '5.0 MB'
    >>> format_size(1073741824)
    '1.0 GB'
"""
You should write code starting with:
def format_size(bytes_size: int) -> str:
    # TODO: Implement this function based on the docstring.
    pass

