lass="token operator">: </span><a href="https://kotlinlang.org/api/core/kotlin-stdlib/kotlin/-double/index.html">Double</a><span class="token operator">?</span><span class="clearfix"><span class="floating-right">(<a href="https://github.com/buszi/Boomerang/src/androidMain/kotlin/io/buszi/boomerang/core/AndroidBoomerang.kt#L66">source</a>)</span></span></div><p class="paragraph">Retrieves a Double value for the given key.</p><span class="kdoc-tag"><h4 class="">Return</h4><p class="paragraph">The Double value