Setting 'd:DataContext' in a ResourceDictionary

<ResourceDictionary
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    mc:Ignorable="d">

    <!-- I wish to set 'd:DataContext="{d:DesignInstance Type=SomeNamespace:SomeViewModel}' for this style, but don't know how -->
    <Style TargetType="{x:Type SomeNamespace:SomeControl}">
        <Setter Property="Y" Value="{Binding Top}"/>
    </Style>
</ResourceDictionary>