def METHOD_NAME(gopkg):
    """
    Gets the location of the go source given go package, based on the $GOPATH.
    """
    gopaths = os.getenv("GOPATH")
    for path in gopaths.split(":"):
        maybe_path = os.path.abspath(os.path.expanduser(os.path.join(
            path, "src", *gopkg.split("/"))))
        if os.path.isdir(maybe_path):
            return maybe_path
    return ""