code: function(name){
          var field = this.fields[name];
          if (!field)
              Xmla.Exception._newError(
                  "INVALID_FIELD",
                  "Xmla.Rowset.fieldDef",
                  name
              )._throw();
          return field;
      }
docs: Retrieves a <code>fieldDef</code> object by name.
  A fieldDef describes a field (column). It has the following properties:
  <dl>
  <dt>label</dt><dd>string. This is the human readable name for this field. You should use this name for display purposes and for building restrictions. This is also the name used for matching againstt the <code>name</code> argument passed to the <code>fieldDef()</code> method.</dd>
  <dt>name</dt><dd>string. This is the (possibly escaped) name of the field as it appears in the XML document</dd>
  <dt>index</dt><dd>int. The ordinal position of this field. Fields are numbered starting from 0.</dd>
  <dt>type</dt><dd>string. The name of the XML data type for the values that appear in this column</dd>
  <dt>minOccurs</dt><dd>string. The minimal number of occurrences of a value. "0" means the field is optional.</dd>
  <dt>maxOccurs</dt><dd>string. If this is parseable as an integer, that integer specifies the number of times a value can appear in this column. "unbounded" means there is no declared limit.</dd>
  <dt>getter</dt><dd>function. This function is used to extract a value from the XML document for this field.</dd>
  </dl>
  @method fieldDef
  @param {string} name The name of the field to retrieve.
  @return {fieldDef} The <code>fieldDef</code> object that matches the argument.