lib/Ext/core/lang/String.js
function(pattern, count, sep) {
        for (var buf = [], i = count; i--; ) {
            buf.push(pattern);
        }
        return buf.join(sep || '');
    }
function(pattern, count, sep) {
        for (var buf = [], i = count; i--; ) {
            buf.push(pattern);
        }
        return buf.join(sep || '');
    }
Returns a string with a specified number of repetitions a given string pattern.
The pattern be separated by a different string.

var s = Ext.String.repeat('---', 4); // '------------'
var t = Ext.String.repeat('--', 3, '/'); // '--/--/--'

@param {String} pattern The pattern to repeat.
@param {Number} count The number of times to repeat the pattern (may be 0).
@param {String} sep An option string to separate each pattern.