KV filter stripping out parentheses

[blaisefonseca]

I am using KV filter to split query string, however, the filter strips parentheses at the beginning and end, how can I avoid this?
Below is my KV filter
kv {
target => "cs_uri_query"
allow_duplicate_values => false
field_split => "&?"
source => "uri_query"
}
which outputs to

cs_uri_query.q = "app:test AND (schema_s:contact" it shoud be cs_uri_query.q = "(app:test AND (schema_s:contact))"

[blaisefonseca]

include_brackets => false fixed my issue