Sometimes the written music has a section showing more than one chord per measure, like this:

Here we have a whole note tied to a quarter note on the next measure, the whole note has the Dmi7 chord above it and the quarter note a Ami7 chord. But a G9 chord appears on the same measure as the whole note, so a G9 chord should be included in the chord table between the Dmi7 and Ami7 chord.
In order to preserve the correct timing and character for this passage when the song is played, the whole note should be converted to a half note, and a second half note tied to the first introduced in the same measure. the above passage would then be converted to this:

And the chord table would look like this:

If in the above example the original tie between the Dmi7 and Ami7 chords did not exists:

you would still need to introduce a tied half note to preserve the continuation of the sound of the whole note (which still needs to be converted to a half note). So the conversion should look like this:

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