public Builder addHistogramQueries(com.google.cloud.talent.v4.HistogramQuery value) {
      if (histogramQueriesBuilder_ == null) {
        if (value == null) {
          throw new NullPointerException();
        }
        ensureHistogramQueriesIsMutable();
        histogramQueries_.add(value);
        onChanged();
      } else {
        histogramQueriesBuilder_.addMessage(value);
      }
      return this;
    }
<pre>
An expression specifies a histogram request against matching jobs.

Expression syntax is an aggregation function call with histogram facets and
other options.

Available aggregation function calls are:
* `count(string_histogram_facet)`: Count the number of matching entities,
for each distinct attribute value.
* `count(numeric_histogram_facet, list of buckets)`: Count the number of
matching entities within each bucket.

A maximum of 200 histogram buckets are supported.

Data types:

* Histogram facet: facet names with format `[a-zA-Z][a-zA-Z0-9_]+`.
* String: string like "any string with backslash escape for quote(&#92;")."
* Number: whole number and floating point number like 10, -1 and -0.01.
* List: list of elements with comma(,) separator surrounded by square
brackets, for example, [1, 2, 3] and ["one", "two", "three"].

Built-in constants:

* MIN (minimum number similar to java Double.MIN_VALUE)
* MAX (maximum number similar to java Double.MAX_VALUE)

Built-in functions:

* bucket(start, end[, label]): bucket built-in function creates a bucket
with range of [start, end). Note that the end is exclusive, for example,
bucket(1, MAX, "positive number") or bucket(1, 10).

Job histogram facets:

* company_display_name: histogram by
[Job.company_display_name][google.cloud.talent.v4.Job.company_display_name].
* employment_type: histogram by
[Job.employment_types][google.cloud.talent.v4.Job.employment_types], for
example,
  "FULL_TIME", "PART_TIME".
* company_size (DEPRECATED): histogram by
[CompanySize][google.cloud.talent.v4.CompanySize], for example, "SMALL",
"MEDIUM", "BIG".
* publish_time_in_day: histogram by the
[Job.posting_publish_time][google.cloud.talent.v4.Job.posting_publish_time]
  in days.
  Must specify list of numeric buckets in spec.
* publish_time_in_month: histogram by the
[Job.posting_publish_time][google.cloud.talent.v4.Job.posting_publish_time]
  in months.
  Must specify list of numeric buckets in spec.
* publish_time_in_year: histogram by the
[Job.posting_publish_time][google.cloud.talent.v4.Job.posting_publish_time]
  in years.
  Must specify list of numeric buckets in spec.
* degree_types: histogram by the
[Job.degree_types][google.cloud.talent.v4.Job.degree_types], for example,
  "Bachelors", "Masters".
* job_level: histogram by the
[Job.job_level][google.cloud.talent.v4.Job.job_level], for example, "Entry
  Level".
* country: histogram by the country code of jobs, for example, "US", "FR".
* admin1: histogram by the admin1 code of jobs, which is a global
  placeholder referring to the state, province, or the particular term a
  country uses to define the geographic structure below the country level,
  for example, "CA", "IL".
* city: histogram by a combination of the "city name, admin1 code". For
  example,  "Mountain View, CA", "New York, NY".
* admin1_country: histogram by a combination of the "admin1 code, country",
  for example, "CA, US", "IL, US".
* city_coordinate: histogram by the city center's GPS coordinates (latitude
  and longitude), for example, 37.4038522,-122.0987765. Since the
  coordinates of a city center can change, customers may need to refresh
  them periodically.
* locale: histogram by the
[Job.language_code][google.cloud.talent.v4.Job.language_code], for example,
"en-US",
  "fr-FR".
* language: histogram by the language subtag of the
[Job.language_code][google.cloud.talent.v4.Job.language_code],
  for example, "en", "fr".
* category: histogram by the
[JobCategory][google.cloud.talent.v4.JobCategory], for example,
  "COMPUTER_AND_IT", "HEALTHCARE".
* base_compensation_unit: histogram by the
  [CompensationInfo.CompensationUnit][google.cloud.talent.v4.CompensationInfo.CompensationUnit]
  of base salary, for example, "WEEKLY", "MONTHLY".
* base_compensation: histogram by the base salary. Must specify list of
  numeric buckets to group results by.
* annualized_base_compensation: histogram by the base annualized salary.
  Must specify list of numeric buckets to group results by.
* annualized_total_compensation: histogram by the total annualized salary.
  Must specify list of numeric buckets to group results by.
* string_custom_attribute: histogram by string
[Job.custom_attributes][google.cloud.talent.v4.Job.custom_attributes].
  Values can be accessed via square bracket notations like
  string_custom_attribute["key1"].
* numeric_custom_attribute: histogram by numeric
[Job.custom_attributes][google.cloud.talent.v4.Job.custom_attributes].
  Values can be accessed via square bracket notations like
  numeric_custom_attribute["key1"]. Must specify list of numeric buckets to
  group results by.

Example expressions:

* `count(admin1)`
* `count(base_compensation, [bucket(1000, 10000), bucket(10000, 100000),
bucket(100000, MAX)])`
* `count(string_custom_attribute["some-string-custom-attribute"])`
* `count(numeric_custom_attribute["some-numeric-custom-attribute"],
  [bucket(MIN, 0, "negative"), bucket(0, MAX, "non-negative")])`
</pre>

<code>repeated .google.cloud.talent.v4.HistogramQuery histogram_queries = 7;</code>
java-talent/proto-google-cloud-talent-v4/src/main/java/com/google/cloud/talent/v4/SearchJobsRequest.java