- 
    Type:Sub-task 
- 
    Resolution: Fixed
- 
    Priority:L3 - Default 
- 
    Affects Version/s: None
- 
    Component/s: None
Affected endpoints:
- deleteAsyncHistoricQueryBased
- deleteProcessInstancesAsync
- setRetriesByProcess
- setRetriesByProcessAsync
- setRetriesByProcessHistoricQueryBasedAsync
- updateSuspensionState
- updateSuspensionStateAsync
- updateSuspensionStateByProcessDefinition
- updateSuspensionStateByProcessDefinitionAsync
- there are affected DTOs as well...
- ...
Example:
    /**
     * 
     * Deletes a set of process instances asynchronously (batch) based on a historic process instance query.
     * @param UNKNOWN_BASE_TYPE  (optional)
     * @return BatchDto
     * @throws ApiException If fail to call the API, e.g. server error or cannot deserialize the response body
     * @http.response.details
     <table summary="Response Details" border="1">
        <tr><td> Status Code </td><td> Description </td><td> Response Headers </td></tr>
        <tr><td> 200 </td><td> Request successful. </td><td>  -  </td></tr>
        <tr><td> 400 </td><td> Bad Request         Returned if some of the query parameters are invalid, i.e., neither processInstanceIds, nor historicProcessInstanceQuery is present </td><td>  -  </td></tr>
     </table>
     */
    public BatchDto deleteAsyncHistoricQueryBased(UNKNOWN_BASE_TYPE UNKNOWN_BASE_TYPE) throws ApiException {
        ApiResponse<BatchDto> localVarResp = deleteAsyncHistoricQueryBasedWithHttpInfo(UNKNOWN_BASE_TYPE);
        return localVarResp.getData();
    }
When:
java -jar openapi-generator-cli-4.2.3.jar generate -i ../camunda-bpm-platform/engine-rest/engine-rest-openapi/target/generated-sources/openapi-json/openapi.json -g java -o ./output
Then:
[main] WARN  o.o.codegen.DefaultCodegen - The following schema has undefined (null) baseType. It could be due to form parameter defined in OpenAPI v2 spec with incorrect consumes. A correct 'consumes' for form parameters should be 'application/x-www-form-urlencoded' or 'multipart/?'
[main] WARN  o.o.codegen.DefaultCodegen - schema: class Schema {
    type: null
    format: null
    $ref: null
    description: null
    title: null
    multipleOf: null
    maximum: null
    exclusiveMaximum: null
    minimum: null
    exclusiveMinimum: null
    maxLength: null
    minLength: null
    pattern: null
    maxItems: null
    minItems: null
    uniqueItems: null
    maxProperties: null
    minProperties: null
    required: null
    not: null
    properties: {suspended=class BooleanSchema {
        class Schema {
            type: boolean
            format: null
            $ref: null
            description: A Boolean value which indicates whether to activate or suspend a given process instance. When the value is set to true, the given process instance will be suspended and when the value is set to false, the given process instance will be activated.
            title: null
            multipleOf: null
            maximum: null
            exclusiveMaximum: null
            minimum: null
            exclusiveMinimum: null
            maxLength: null
            minLength: null
            pattern: null
            maxItems: null
            minItems: null
            uniqueItems: null
            maxProperties: null
            minProperties: null
            required: null
            not: null
            properties: null
            additionalProperties: null
            nullable: null
            readOnly: null
            writeOnly: null
            example: null
            externalDocs: null
            deprecated: null
            discriminator: null
            xml: null
        }
    }}
    additionalProperties: null
    nullable: null
    readOnly: null
    writeOnly: null
    example: null
    externalDocs: null
    deprecated: null
    discriminator: null
    xml: null
}
[main] WARN  o.o.codegen.DefaultCodegen - codegenModel is null. Default to UNKNOWN_BASE_TYPE
[main] WARN  o.o.codegen.utils.ModelUtils - Multiple schemas found in content, returning only the first one
[main] WARN  o.o.codegen.utils.ModelUtils - Multiple schemas found in content, returning only the first one
[main] WARN  o.o.codegen.DefaultCodegen - allOf with multiple schemas defined. Using only the first one: DeleteProcessInstancesDto. To fully utilize allOf, please use $ref instead of inline schema definition
Expected:
No UNKNOWN_BASE_TYPE warnings during the generation of java client from the openapi.json