React native: How to stylize native Picker(border and arrow)?

In docs there is no info about what styles is supported for Picker.

I trying to make components Picker alongside TextInput, all my attempts to style Picker the same way I'm styling TextInput fail.

So I ask You to help me to style border , borderRaduis, borderWidth for Picker.

And maybe You know how to customise arrow sign in Picker.

A simplified version of my code, see below :

<View>
    <View>
        <Picker
            selectedValue={this.state.source}
            style={{
               // Styles here 
            }}
              onValueChange={(itemValue, itemIndex) =>
                  this.setState({ source: itemValue })
              }
        >
            <Picker.Item label="Item-1" value="item1" />
            <Picker.Item label="Item-2" value="item2" />
        </Picker>
    </View>
</View>

Thanks for your attention. I’m looking forward to your reply.

I hope it will work to give you Picker Border ...

          <View style={{  alignItems: 'center', borderColor: 'black', borderWidth: 1, borderRadius: 5, width: '60%', backgroundColor: 'transparent'  }}>
              <Picker
                 selectedValue={this.state.source}
                 style={{
                   height: 30,width: "100%",
                    }}
                 onValueChange={(itemValue, itemIndex) =>
                     this.setState({ source: itemValue })
                    }
                >
               <Picker.Item label="Item-1" value="item1" />
               <Picker.Item label="Item-2" value="item2" />
           </Picker>
        </View>