CSVRecordSetWriter quotes numeric values when Quote Mode set to Quote Non-Numeric Values

When the CSVRecordSetWriter is configured with a quote mode of "Quote Non-Numeric Values" it still quotes the numeric values. For example, given the following schema:

{
  "name": "myschema",
  "namespace": "test",
  "type": "record",
  "fields": [
      { "name": "name", "type": "string" },
      { "name": "age", "type": "int" }
  ]
} 

And the following JSON as a representation of a Record:

{
  "name": "John Doe", "age": 30
} 

The output looks like this:

"name","age"
"John Doe","30"

When it should look like this:

"name","age"
"John Doe",30