Setting this property checks the current value of the RenderObject property. If it is a RenderText, the value is assigned to that object's Text.
Otherwise, a new RenderText initialized with value is created and assigned to RenderObject. Note that properties from the old RenderObject are copied to the newly created RenderText using the RenderObject.AssignFrom method. In particular, this copies the style from the old object to the new one.
Getting this property returns Text of RenderText assigned to the RenderObject on the current cell, or an empty string if the current value of RenderObject is not a RenderText.