Cannot read property 'number' of undefined

```
React Native Environment Info:
System:
OS: Linux 4.15 Ubuntu 18.04.2 LTS (Bionic Beaver)
CPU: (8) x64 Intel(R) Core(TM) i7-6700HQ CPU @ 2.60GHz
Memory: 2.32 GB / 11.63 GB
Shell: 5.4.2 - /bin/zsh
Binaries:
Node: 8.10.0 - /usr/bin/node
Yarn: 1.17.3 - /usr/bin/yarn
npm: 3.5.2 - /usr/bin/npm
npmPackages:
react: 16.8.3 => 16.8.3
react-native: 0.59.8 => 0.59.8
npmGlobalPackages:
react-native-cli: 2.0.1
```

```javascript
import CircularSlider from 'react-native-circular-slider';
```


Start by reproducing the reported `import CircularSlider from 'react-native-circular-slider'` in the listed React Native environment and capture the full stack trace. Inspect the package entry point and determine why the imported value is undefined; done means the import no longer throws and the relevant behavior is covered by a verified reproduction.

Written by the indexing model from the issue text.