docs: function getImportSources(filePath, parserOpts, extensions) {
    let importSources = [];
    if (extensions.indexOf(path.extname(filePath).replace('.', ''))> -1 ) {
      let file = loadFileSync(filePath, parserOpts);
      for (let item of file.path.get('body')) {
        if (item.isImportDeclaration() || (item.isExportDeclaration() && item.node.source)) {
          importSources.push(item.node.source.value);
        }
      }
    }
    
    return importSources;
  }