Cannot fit requested classes in a single dex file (# methods: 65785 > 65536) code example

Example 1: Cannot fit requested classes in a single dex file (# methods: 65710 > 65536)

android {
    defaultConfig {
        ...
        minSdkVersion 21 <----- *here
        targetSdkVersion 26
        multiDexEnabled true <------ *here
    }
    ...
}

Example 2: Cannot fit requested classes in a single dex file (# methods: 65710 > 65536)

def multidex_version = "2.0.1"
 implementation 'androidx.multidex:multidex:$multidex_version'