\environment columnsets-000

\definecolumnset[example][n=4,page=left]

\starttext

\startbuffer
\fakewords{100}{200}
\placefigure
  {}
  {\externalfigure[placeholder][width=\columnsetspanwidth{1}]}
\fakewords{100}{200}
\placefigure
  {}
  {\externalfigure[placeholder][width=\columnsetspanwidth{2}]}
\fakewords{100}{200}
\stopbuffer

\startcolumnset[example]

  \dorecurse {5}{\getbuffer}
  \dorecurse{10}{\fakewords{100}{200}\par}

\stopcolumnset

\stoptext