human
I wrote the below code

    def starts_with(value):
        validate(text, value)
        if (not value.startswith(string)):
            raise ValueError("'{0}'    does    not    start    with    '{1}'".format(value, string))
        return True
    return starts_with

What's a good function header?
assistant
#Here's a good function header.

def startswith(string):