Please help me write the following method: public static java.lang.String mergePreservingRuns(java.lang.String t, java.lang.String s) 

Merges two strings together, using alternating characters from each, except that runs of the same character are kept together. For example,

mergePreservingRuns("abcde", "xyz") returns "axbyczde"

mergePreservingRuns("abbbbcde", "xyzzz") returns "axbbbbyczzzde"

Either or both of the strings may be empty. If the first string is nonempty, its first character will be first in the returned string.

Parameters:

t - first string

s - second string

Returns:

string obtained by merging characters from t and s, preserving runs