When using this syntax, the rendered result adds a blank line between the 2 @ directive. In fact, it seems to add a blank line before the @ symbol.
Code
@using Microsoft.Extensions
@inherits ComponentBase
<span>Test</span>
@using Microsoft.AspNetCore
<span>Test</span>
Rendered HTML
<code class="language-cshtml-razor hljs" data-highlighted="yes"><span class="hljs-built_in">@using</span><span class="hljs-type"> Microsoft.Extensions</span>
<span class="hljs-built_in">
@inherits</span><span class="hljs-type"> ComponentBase</span>
<span class="hljs-tag"><<span class="hljs-name">span</span>></span>Test<span class="hljs-tag"></<span class="hljs-name">span</span>></span>
<span class="hljs-built_in">
@using</span><span class="hljs-type"> Microsoft.AspNetCore</span>
<span class="hljs-tag"><<span class="hljs-name">span</span>></span>Test<span class="hljs-tag"></<span class="hljs-name">span</span>></span>
</code>
Result

When using this syntax, the rendered result adds a blank line between the 2 @ directive. In fact, it seems to add a blank line before the @ symbol.
Code
Rendered HTML
Result