Because your code isn't indented properly. We can't see that from those 2 lines you provided.
With simple words, if your code looks like this:
PHP Code:
function()
{
some_code()
more_code()
}
You should make it look like this:
PHP Code:
function()
{
some_code()
more_code()
}
Inconsistent usage of tabs and regular spaces can also cause that warning.
Bear in mind this is only a warning and doesn't have any effect on the plugin.
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