function validateConditionalFiles(conditionalFiles) {
  if (typeof conditionalFiles === 'object') {
    const fileNames = Object.keys(conditionalFiles);

    fileNames.forEach(fileName => {
      const def = conditionalFiles[fileName];
      if (typeof def.subject !== 'string') throw new Error(`Invalid conditional file subject for ${fileName}: ${def.subject}.`);
      if (typeof def.validation !== 'object') throw new Error(`Invalid conditional file validation object for ${fileName}: ${def.validation}.`);
      conditionalFiles[fileName].validate = ajv.compile(conditionalFiles[fileName].validation);
    });
  }
}
Checks if conditional files are specified properly in the template
@private
@param {Object} conditionalFiles conditions specified in the template config