Create additional signingConfigs for current productFlavor

I have two different sign certificates.How to create additional signingConfigs for dev2 productFlavors.

productFlavors {        dev {            applicationId "dev.app"            dimension "default"        }        dev2 {            applicationId "dev2.app"            dimension "default"        }    }signingConfigs {        releaseConfig {            storeFile file(getProperty.getProperty("key.store"))            storePassword getProperty.getProperty("key.store.password")            keyAlias getProperty.getProperty("key.alias")            keyPassword getProperty.getProperty("key.alias.password")        }        debugConfig {        }    }