genClassProps(ast) {
    const topParent = this.isAstTopParent(ast)
    const classAttrsValue = ast.attrs
      .filter(v => v.name === 'class')
      .map(v => v.value)
    if (classAttrsValue.length === 0 && !topParent) {
      return
    }
    let staticClass, dynamicClass
    classAttrsValue.forEach(v => {
      if (/^".*"$/.test(v) || /^'.*'$/.test(v)) {
        staticClass = v.trim() // .replace(/^"(.*)"$/, '$1')
      } else {
        dynamicClass = v
      }
    })
    let objCode = '{'
    if (staticClass) {
      objCode += `staticClass: ${staticClass},`
    }
    if (dynamicClass) {
      objCode += `dynamicClass: ${dynamicClass},`
    }
    if (topParent) {
      objCode += `parentClass: this.props.style,`
    }
    objCode = `${objCode.replace(/,$/, '')}}`
    return `${NATIVE.bindClass.name}.call(this, ${objCode})`
  }
gen class props
@param {Object} ast