private JsonTestCaseReader<S> parseFile(final File file) {
    final JavaType javaType =
        objectMapper
            .getTypeFactory()
            .constructParametricType(JsonTestCaseReader.class, jsonFileMappedType);

    try {
      return objectMapper.readValue(file, javaType);
    } catch (final IOException e) {
      throw new RuntimeException(
          "Error parsing test case file " + file + " to class " + jsonFileMappedType, e);
    }
  }
Generate collection.

@param filteredFiles the filtered files
@return the collection
testutil/src/main/java/org/hyperledger/besu/testutil/JsonTestParameters.java