public SoqlStringContainsExpression(SoqlExpression haystack, SoqlStringContainsPosition position, string needle)
 {
     this.haystack = haystack;
     this.position = position;
     this.needle = needle;
 }
 public SoqlStringContainsExpression(SoqlExpression haystack, SoqlStringContainsPosition position, string needle)
 {
     this.haystack = haystack;
     this.position = position;
     this.needle   = needle;
 }