def METHOD_NAME(self, file):
    """Extract the list of includes from the given file."""
    deps = set()
    with open(os.path.join(self.root, file), encoding='utf-8') as file:
        for line in file:
            if line.startswith('namespace dart {'):
                break
            m = INCLUDE_DIRECTIVE_RE.match(line)
            if m is not None:
                header = os.path.join('runtime', m.group(1))
                if os.path.isfile(os.path.join(self.root, header)):
                    deps.add(header)
    return deps