Question on ProjectMergeRule

[Homer]

Hi

The ProjectMergeRule 
<https://calcite.apache.org/apidocs/org/apache/calcite/rel/rules/ProjectMergeRule.html> 
specifies the following

ProjectMergeRule merges a |Project| 
<https://calcite.apache.org/apidocs/org/apache/calcite/rel/core/Project.html> 
into another |Project| 
<https://calcite.apache.org/apidocs/org/apache/calcite/rel/core/Project.html>, 
provided the projects aren't projecting identical sets of input references.

I would like to get rid of identical projection in a plan, but this rule 
specifically doesn't remove identical projections

i am wondering if there is a standard rule that will remove identical 
projections.

Also curious why we dont want to merge identical rules in the 
ProjectMergeRule case?

thanks