import re


def get_label(file):
    """
    Read lines of a file and try to find a doxygen label.
    If the label is not found return None.
    Assume the label is in the first line
    """
    with open(file, 'r', encoding='utf-8') as f:
        line = f.readline()
        label = re.search(r'\{\#(.+)\}', line)
        if label:
            return label.group(1)