    H1 Header
    =========

    H2 Header
    ---------

    H1 Header, underline could be of any length
    =

    H2 Header, underline could be of any length
    -

    H1 Header, underline could be of any length

    H2 Header, underline could be of any length

    This is not an header because the underline must begin at the beginnning of the line
     =

    This is not an header because the underline must begin at the beginnning of the line
    .=