Searches a multi-line string and returns the first line begining with the specified prefix.
The prefix may be included with or omitted from the return string.
Parameters
str: string
The string to be searched.
prefix: string
The string to locate at the beginning of a line.
includePrefix: boolean
A flag indicating whether the prefix is to be included in the return value.
Returns string | undefined
The requested line or undefined if the prefix was not located.
Searches a multi-line string and returns the first line begining with the specified prefix. The prefix may be included with or omitted from the return string.