Function: first()
first(
this,left):unknown
Return the first item of the input sequence. The input could be array-like or a mapping, but not a string.
Parameters
• this: FilterContext
An object containing a reference to the active render context and any keyword/named arguments.
• left: unknown
Any value.
Returns
unknown
The first item in the input iterable, or null if the input value
is not iterable, or undefined if the iterable is empty.