CustomMerge2
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Implement your own merging logic to mix merging modes.

The C1FlexGrid control offers several built-in merging modes (free,
spill, nodes, row/col control, etc). But there are some limitations.
For example, none of the built-in modes allows you to create merged
ranges that span both rows and columns.

This sample shows how you can overcome this limitation by inheriting
from the C1FlexGrid and implementing a custom version of the virtual
GetMergeRange method.

To see the effect of the custom merging, set the following:

1) "AllowMerging" to Free
2) "Rows" checkbox to true
3) "Cols" checkbox to false

Then click the "Custom" checkbox and watch how the header changes.
