code: function validate(globs, options) {
      let hasError = false
  
      if (globs == null || globs.length === 0) {
          console.error("ERROR: requires file globs.")
          hasError = true
      }
      if (options.output != null && Array.isArray(options.output)) {
          console.error("ERROR: --output option should not be multiple.")
          hasError = true
      }
      if (options.prefix != null) {
          if (Array.isArray(options.prefix)) {
              console.error("ERROR: --prefix option should not be multiple.")
              hasError = true
          }
      }
      if (options.verbose && !options.output) {
          console.error("ERROR: --verbose option should be used together with --output option.")
          hasError = true
      }
      if (options.watch && !options.output) {
          console.error("ERROR: --watch option should be used together with --output option.")
          hasError = true
      }
  
      return !hasError
  }
docs: Validate options.
  
  @param {string[]} globs - The globs which specifies the target files.
  @param {object} options - The option object.
  @returns {boolean} `true` if the option object is valid.
  @private